Can't Enter text in a table

I created a table and now I want to enter text into the table.   I select the table and then select the tab 'Table'.  The help pages say to select a cell and type the text.  All those options are grayed out.  The only options are to create a table or delete the selected table.

I enable the text tab and then clicked on a cell in the table.  I type, but nothing shows.  I go to edit the text in the cell and see what I typed, but exiting edit still does not show the text in the cell.

Advice?