to "paint" the cell grid yourself.  They look like
this::

   +------------------------+------------+----------+----------+
   | Header row, column 1   | Header 2   | Header 3 | Header 4 |
   | (header rows optional) |            |          |          |
   +========================+============+==========+==========+
   | body row 1, column 1   | column 2   | column 3 | column 4 |
   +------------------------+------------+----------+----------+
   | body row 2             | ...        | ...      |          