I was thinking of something simple...
But there is never a simple answer here.
I first thought computers... but the cost and hassle, isn't worht it, and try to get data from publishers..
We are talking books..
Publishers should donate a few books to the club for reference during the show.
Leave them behind the table.
Everyone who enters the room has a badge. Let them sign for the books. If the book is lost, charge them..