Example 1:
DataTable dtMain = new DataTable();
dtMain.Columns.Add("dataTable", typeof(object));
DataTable dt1 = new DataTable();
DataTable dt2 = new DataTable();
dtMain.Rows.Add(dt1);
dtMain.Rows.Add(dt2);
Example 2:
DataTable dtMain = new DataTable();
dtMain.Columns.Add("dataTable", typeof(DataTable));
DataTable dt1 = new DataTable();
DataTable dt2 = new DataTable();
dtMain.Rows.Add(dt1);
dtMain.Rows.Add(dt2);