create columsn and rows with c# code example

Example: C# create DataTable

DataTable dt = new DataTable(); 
dt.Clear();
dt.Columns.Add("Name");
dt.Columns.Add("Marks");

DataRow _ravi = dt.NewRow();
_ravi["Name"] = "ravi";
_ravi["Marks"] = "500";
dt.Rows.Add(_ravi);