Looking at the documentation it doesn't appear that you can put HTML tags there. Then again, even HTML itself doesn't allow a <div>
tag directly inside a <table>
tag, so I'm not sure why you'd want to do this.
According to the FAQ:
How can I display static headers in a table, so that headers remain visible while user scrolls the table body?
You can do that simply using css, adding an height and the overflow: scroll property to the tbody element. Unfortunately this will work perfectly in Netscape/Mozilla, but not in Internet Explorer.
A table with a scrollable body can be made in Internet Explorer using javascript or a more complex css. Here you can find a good css example.
And some more info here.