Chocolate.  Go ahead and laugh, it works.  Little chocolate bars. Especially in Gold or silver wrappers.  They will flock to the table, and that is your first step.

get 2 hot girls in bikinis to stand at your both>>>  WORKS FOR JIM DINES NEWSLETTER. (goldbugs understand)   Raffle is a must, build a money tree and have them guess how much cash is on it.  worked ok for me in the mid-90’s

Give out Tote Bags with your logo on them.  People at trade shows are always looking for either food or something to help them carry all the swag that other people are handing out.