How to track

unfortunately No, I do not even know of any tracking software developed for Tablets yet. There are ways for some phones and installed software and PCs if the software is installed. I am afraid unless it is found and returned, you have suffered a loss.
Not that is does any good now, but there is an app called Lookout that does provide this functionality to a point.

Just a thought, is there any chance your tablet had GPS, and that you had joined latitude? That way if they turn it on, and haven't flashed it Google Maps would show where the tablet is.

Sorry that happened, that stinks!