"So isn't the gun show at some fault here?
If their rules are that you need a FFL to sell guns, then WHY did this non-FFL have a table(setup) to sell at this gun show.
Why did they allow him there w/o a license? "
Some shows have stations set up, or arrangements made for someone with an FFL to be available, to run the background checks for the non-FFL sellers. I've seen them, I just haven't used one or paid attention to the details of the arrangements.