static void Main(string[] args) { DataTable table1 = new DataTable(); table1.Columns.Add("Column1"); table1.Columns.Add("Column2"); table1.Columns.Add("Column3"); table1.Rows.Add(new object[] { "Value1", "Value2", "Value3" }); table1.Rows.Add(new object[] { "Value21", "Value22", "Value23" }); table1.Rows.Add(new object[] { "Value31", "Value32", "Value33" }); DataTable table2 = new DataTable(); table2.Columns.Add("Column1"); table2.Columns.Add("Column2"); table2.Columns.Add("Column3"); table2.Rows.Add(new object[] { "Value221", "Value222", "Value223" }); table2.Rows.Add(new object[] { "Value2221", "Value2222", "Value2223" }); table2.Rows.Add(new object[] { "Value2231", "Value2232", "Value2233" }); string filename = "thisfile.xlsx"; AyishayWriter writer = new AyishayWriter(filename); writer.DatatableToExcel(table1, "table1"); writer.DatatableToExcel(table2, "table2"); writer.saveExcel(); Console.ReadKey(); }