I wanted to try last year, but I added Thursday at the last minute, so I was staying in Strasburg. Decided to make that trip early.
Still, with that many people, and not knowing anyone, it sounds a bit intimidating. Staying in York this year, so I’ll see how I feel. Certainly don’t want to sit in my room eating Royal Farms again.
Chris, the object of the exercise it to meet people at the gathering. 
Don't be intimidated by "Gunrunner" in John's forum handle. As long as you buy one of his Super-Chuffers he'll be nice to you!
Seriously though. I was like you my first trip to York - didn't know a soul. As some are aware, I have OCD and take medicine so the fact I have it is pretty much transparent to everyone unless you already know. My point is new situations which I have no control over are not my favorite types of situations to be in. Situations exactly like the forum breakfast Thursday at Round the Clock diner, the OGR dinner Thursday night, or any of the open houses for which public invitations are given in a forum post or announcement.
The hardest part of meeting new people - finding common ground, is already taken care of. We all are into toy trains which provides numerous topics for conversation beyond the ritual name, place of residence, etc. In fact, you'll find the majority of conversations are about anything but trains once folks get to know each other.
By all means, please come out to the breakfast and the dinner on Thursday's if you are able. There is a thread started by Peter Condro (Putnam Division) on the York Forum which lists the particulars on the breakfast. At either event, if there are no empty tables just ask to sit at any open seat (some get saved for friends arriving late) and introduce yourself. If there is an open table, then folks will be asking you if empty seats are taken before long. The rest will take care of itself.
For the dinner - once folks are done eating we generally start to move around in order to talk to as many folks as we can to catch up. By no means is it a "static" dinner event - more like a banquet/reception atmosphere.
I will have my York badge on at both events. Please feel free to seek me out and introduce yourself - I'd be glad to meet you and introduce you to others. If you continue to attend York and these events you'll know plenty of folks before you know it. 
-Greg
