There's no way to create a DataTable from what the code you've posted.
You would have to craft the columns in the DataTables yourself, possibly even adding a foreign key relationship between them.
DataTable table1 = new DataTable();
table1.Columns.Add("Id", typeof(int));
table1.Columns.Add("Field1", typeof(int));
table1.Columns.Add("Field2", typeof(string));
table1.Columns.Add("Field3", typeof(string));
DataTable table2 = new DataTable();
table2.Columns.Add("Id", typeof(int));
table2.Columns.Add("table1FK", typeof(int));
table2.Columns.Add("Fld1", typeof(int));
table2.Columns.Add("Fld2", typeof(int));
table2.Columns.Add("Fld3", typeof(decimal));
DataSet ds = new DataSet();
ds.Tables.Add(table1);
ds.Tables.Add(table2);
ds.Relations.Add("MasterDetail", table1.Columns["Id"], table2.Columns["Id"]);