Hey! I pretty much ran our 8th grade night, so I can let you know what we did.
At our table, we had some info packets in folders and a laptop playing random videos from all 3 years (This years animation, shop videos, match videos from the blue alliance, ect..).
As well as that, we boxed off a big area with tables and put the robot and a soccer net inside, with the controls on one of the tables, and let the kids drive it around. (Make sure you have bumpers on!)
Other then that, thats about it. Just make sure the person at the info table knows what he/she is talking about, and points them to the "HEY, drive a robot!" station.
We also sold hexbugs, but I dunno if you have them
. They make a good demonstration at the info table.