I finally discovered Sweet Tomatoes.

I read a list of restaurants recommended for vegans one day. Then, while walking with a friend, I saw the restaurant in the distance. I said, "let's go over and get a sample menu." I thought it was a sit-down restaurant where you order from a menu. And, for some reason, I had the impression it was expensive.
We already had lunch so we just went in to look around. This was on Saturday and it was very crowded. First of all we went in the wrong door and didn't know which door was the right door. But we walked around and did some looking and no one questioned it. It seems nice.
I finally found the cash register and a woman did some explaining about the foods they offer. But now I'm wondering why the cash register is at the end of a line about 30 feet long. What's the purpose of that first line? Is it just for getting a tray, dishes, utensils etc.?
Also, I assume it's an all you can eat buffet for $11.50. Is that correct?
I'm planning on going there sometime before the end of the month and wonder what's the best day to avoid a large crowd.