I went to one last year. Mostly a big raffle with some reasonable tickets, some $100 tickets. A very good steak dinner. Met some friends. Pretty much a fund raiser. My ticket was free through my club.
I always get invited but never go due to work schedule. I heard from other friends that it is more of a fundraiser with high end products to be auctioned off.
You generally get a nice dinner and get to hang out with people who like guns. It's a fun event. Yes, there's an auction and lots of drawings - and they include firearms. Sometimes there may even be a silent auction added in. FNRA dinners are fundraisers and the money goes to local programs to build support at the grassroots level. FNRA money goes to things like kid's shooting programs (4H, for example), or to improve ranges for law enforcement.