Perhaps it's time to learn some web fundamentals?
Dreamweaver expects you to know HTML and CSS.
If you don't know anything then you'll be confused everytime you click your mouse and are faced with another Dreamweaver dialogue box.
I haven’t a clue what a table cell is.
<td>This text is inside a table cell</td>
If you have no tables on your page, you can't modify something that isn't there. Perhaps that's why the options are not available (grayed out).