The sample demonstrates how to insert SparkLine into an excel workbook.

using Spire.Xls;
using System.Drawing;

namespace SparkLine
{
    class Program
    {
        static void Main(string[] args)
        {
            Workbook workbook = new Workbook();
            workbook.Version = ExcelVersion.Version2010;
            workbook.CreateEmptySheets(1);

            Worksheet sheet = workbook.Worksheets[0];

            //Country
            sheet.Range["A1"].Value = "Country";
            sheet.Range["A2"].Value = "Cuba";
            sheet.Range["A3"].Value = "Mexico";
            sheet.Range["A4"].Value = "France";
            sheet.Range["A5"].Value = "German";

            //Jun
            sheet.Range["B1"].Value = "Jun";
            sheet.Range["B2"].NumberValue = 0.23;
            sheet.Range["B3"].NumberValue = 0.37;
            sheet.Range["B4"].NumberValue = 0.15;
            sheet.Range["B5"].NumberValue = 0.25;

            //Jul
            sheet.Range["C1"].Value = "Jul";
            sheet.Range["C2"].NumberValue = 0.1;
            sheet.Range["C3"].NumberValue = 0.35;
            sheet.Range["C4"].NumberValue = 0.22;
            sheet.Range["C5"].NumberValue = 0.33;


            //Aug
            sheet.Range["D1"].Value = "Aug";
            sheet.Range["D2"].NumberValue = 0.14;
            sheet.Range["D3"].NumberValue = 0.36;
            sheet.Range["D4"].NumberValue = 0.25;
            sheet.Range["D5"].NumberValue = 0.25;


            //Sep
            sheet.Range["E1"].Value = "Sep";
            sheet.Range["E2"].NumberValue = 0.17;
            sheet.Range["E3"].NumberValue = 0.28;
            sheet.Range["E4"].NumberValue = 0.39;
            sheet.Range["E5"].NumberValue = 0.32;

            //Style
            sheet.Range["A1:E1"].Style.Font.IsBold = true;
            sheet.Range["A2:E2"].Style.KnownColor = ExcelColors.LightYellow;
            sheet.Range["A3:E3"].Style.KnownColor = ExcelColors.LightGreen1;
            sheet.Range["A4:E4"].Style.KnownColor = ExcelColors.LightOrange;
            sheet.Range["A5:E5"].Style.KnownColor = ExcelColors.LightTurquoise;

            //Border
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeTop].Color = Color.FromArgb(0, 0, 128);
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeTop].LineStyle = LineStyleType.Thin;
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeBottom].Color = Color.FromArgb(0, 0, 128);
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeBottom].LineStyle = LineStyleType.Thin;
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeLeft].Color = Color.FromArgb(0, 0, 128);
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeLeft].LineStyle = LineStyleType.Thin;
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeRight].Color = Color.FromArgb(0, 0, 128);
            sheet.Range["A1:E5"].Style.Borders[BordersLineType.EdgeRight].LineStyle = LineStyleType.Thin;

            sheet.Range["B2:D5"].Style.NumberFormatIndex = 9;

            SparklineGroup sparklineGroup
                = sheet.SparklineGroups.AddGroup(SparklineType.Line);
            SparklineCollection sparklines = sparklineGroup.Add();
            sparklines.Add(sheet["B2:E2"], sheet["F2"]);
            sparklines.Add(sheet["B3:E3"], sheet["F3"]);
            sparklines.Add(sheet["B4:E4"], sheet["F4"]);
            sparklines.Add(sheet["B5:E5"], sheet["F5"]);

            workbook.SaveToFile("Sample.xlsx");
            System.Diagnostics.Process.Start(workbook.FileName);

        }
    }
}

Imports Spire.Xls
Imports System.Drawing
Module Module1
    Sub Main()
        Dim workbook As New Workbook()
        workbook.Version = ExcelVersion.Version2010
        workbook.CreateEmptySheets(1)

        Dim sheet As Worksheet = workbook.Worksheets(0)

        'Country
        sheet.Range("A1").Value = "Country"
        sheet.Range("A2").Value = "Cuba"
        sheet.Range("A3").Value = "Mexico"
        sheet.Range("A4").Value = "France"
        sheet.Range("A5").Value = "German"

        'Jun
        sheet.Range("B1").Value = "Jun"
        sheet.Range("B2").NumberValue = 0.23
        sheet.Range("B3").NumberValue = 0.37
        sheet.Range("B4").NumberValue = 0.15
        sheet.Range("B5").NumberValue = 0.25

        'Jul
        sheet.Range("C1").Value = "Jul"
        sheet.Range("C2").NumberValue = 0.1
        sheet.Range("C3").NumberValue = 0.35
        sheet.Range("C4").NumberValue = 0.22
        sheet.Range("C5").NumberValue = 0.33


        'Aug
        sheet.Range("D1").Value = "Aug"
        sheet.Range("D2").NumberValue = 0.14
        sheet.Range("D3").NumberValue = 0.36
        sheet.Range("D4").NumberValue = 0.25
        sheet.Range("D5").NumberValue = 0.25


        'Sep
        sheet.Range("E1").Value = "Sep"
        sheet.Range("E2").NumberValue = 0.17
        sheet.Range("E3").NumberValue = 0.28
        sheet.Range("E4").NumberValue = 0.39
        sheet.Range("E5").NumberValue = 0.32

        'Style
        sheet.Range("A1:E1").Style.Font.IsBold = True
        sheet.Range("A2:E2").Style.KnownColor = ExcelColors.LightYellow
        sheet.Range("A3:E3").Style.KnownColor = ExcelColors.LightGreen1
        sheet.Range("A4:E4").Style.KnownColor = ExcelColors.LightOrange
        sheet.Range("A5:E5").Style.KnownColor = ExcelColors.LightTurquoise

        'Border
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeTop).Color = Color.FromArgb(0, 0, 128)
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeTop).LineStyle = LineStyleType.Thin
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeBottom).Color = Color.FromArgb(0, 0, 128)
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeBottom).LineStyle = LineStyleType.Thin
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeLeft).Color = Color.FromArgb(0, 0, 128)
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeLeft).LineStyle = LineStyleType.Thin
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeRight).Color = Color.FromArgb(0, 0, 128)
        sheet.Range("A1:E5").Style.Borders(BordersLineType.EdgeRight).LineStyle = LineStyleType.Thin

        sheet.Range("B2:D5").Style.NumberFormatIndex = 9

        Dim sparklineGroup As SparklineGroup = sheet.SparklineGroups.AddGroup(SparklineType.Line)
        Dim sparklines As SparklineCollection = sparklineGroup.Add()
        sparklines.Add(sheet("B2:E2"), sheet("F2"))
        sparklines.Add(sheet("B3:E3"), sheet("F3"))
        sparklines.Add(sheet("B4:E4"), sheet("F4"))
        sparklines.Add(sheet("B5:E5"), sheet("F5"))

        workbook.SaveToFile("Sample.xlsx")
        System.Diagnostics.Process.Start(workbook.FileName)

    End Sub
End Module