Return a table of *width* having *rows* rows and *cols* columns,
        newly appended to the content in this container. *width* is evenly
        distributed between the table columns.

def add_table(self, rows, cols, width):
        """
        Return a table of *width* having *rows* rows and *cols* columns,
        newly appended to the content in this container. *width* is evenly
        distributed between the table columns.
        """
        from .table import Table
        tbl = CT_Tbl.new_tbl(rows, cols, width)
        self._element._insert_tbl(tbl)
        return Table(tbl, self)