Or, instead of all the ones Rawhide gave you (and others in this thread - because there are some that work), you could just, Oh I don't know... press the "Create Table" button? It's the one right under the "Bold" button.

And... if you don't like working with the code, you can turn on WYSIWYG mode, with the button right above the "Bold" button. Then when you create the table with the button, you see the actual blank cells.