I've been there twice, but I'm heading down a few days after it all ends this year instead.
We have never had to wait more than 20-25 min for any resturant. We tend to eat a little earlier than most others.
My tips are these:
1) talk to people and figure out where the other events are going to be. 4x4 outpost has a customer appreciation party and do a BBQ and have a few vendors there us all with some demos, sales, raffles, that type of thing. There is the quadratec bbq as well. Worth hitting if it's not raining and snowing and blowing like last year.
So go to those things, and I'm sure on the book of faces there are groups that tell about such things.
2) stop and talk to vendors about products, learn abut what is out there, see how it compares to others, and see how the company reps feel about their products. I have bought products because the folks there were good people and i have absolutely sworn off others because the company guys were total skid marks (cough- crazy beaver tools- cough cough). They are usually parked all over and doing different things on different days, it's not just the trade show that has cool stuff out. Listen to the local radio station, they will advertise some of these things and their locations.
3) go find some trails that aren't being run by EJS (on an off day) and explore. Find some Indian paintings and some of the less visited arches. Pdf maps are fantastic inventions. Link up with some people that know the area and learn some new things. I was so overwhelmed by it all on the first time I went that I actually feel I missed out on so much. My second visit was head and shoulders better and it was because I had 2 friends there that had also been there previously and we weren't afraid to go explore and try things.
4) come back again, because you will have a ton more fun once you know where things are and are comfortable getting around.