That is going to depend on a heck of a lot of factors, like "where is your information coming from?" and "where is the table data going to go?" but the basic table is pretty easy:
DataTable dt = new DataTable();
dt.Columns.Add("day");
dt.Columns.Add("sub1");
dt.Columns.Add("sub2");
dt.Rows.Add("mon", "hindi", "eng");
dt.Rows.Add("tues", "eng", "math");
dt.Rows.Add("thu", "math", "history");