Something is not right. As stated earlier, plug into iTunes and try seeing what's up. Also, I have a couple 1+ gig games on my 16 gig iPad 2, and still have plenty of space left. Not a big deal, like previous suggested, since there is a MAJOR differences between the list and available.
That's just over 3GB's even with RR3, so I'd hook it up to iTunes. Resetting it might help if you don't see anything on iTunes. Go to "On This iPad" in iTunes if you're new to iOS devices.