Hello,

You may want to look at Elerium HTML to PDF component. It allows to convert html string/file/url to PDF including styles, but it is not free.

I used C# Excel Writer in my project to work with excel. You can use this example below to accomplish your task:

ExcelWorkbook wb = new ExcelWorkbook();
wb.Worksheets.Add("sh1");
wb.Worksheets[0].Cells["A1"].Value = "text";
wb.Worksheets.Add("sh2");
wb.Worksheets[1].Cells["A1"].Value = "text";
wb.Worksheets.Add("sh3");
wb.Worksheets[2].Cells["A1"].Value = "text";
wb.WriteXLSX(@"c:\output.xlsx");

Or, if you want to add data into existing excel file:

ExcelWorkbook Wbook = ExcelWorkbook.ReadXLSX(@"c:\test.xlsx");
Wbook.Worksheets.Add("sh1");
Wbook.Worksheets[Wbook.Worksheets.Count - 1].Cells["A1"].Value = "text";
Wbook.WriteXLSX(@"c:\test.xlsx");