It would be but would take some work to add events to all items in the context menu to show and hide the submenus.

The way I've handled it is to check if I'm on a certain element and then add new elements to the context menu accordingly. So, if you clicked on a link you'd see something like:

Edit Link...
Remove Link
------------
Cut
Copy
Paste

But if you right-clicked within a table cell you'd see:

Cell Properties
Table Properties
---------------
Cut
Copy
Paste

I hope that helps!