What does Auggie imagine everyone is doing in the cafeteria and what does he think is the reason?

Auggie believes that he's been ditched, that everyone in the cafeteria was watching him...... he felt as if he had no friends.

I hoped lunch would be better, but it wasn’t. I sat down at my usual table with Luca and Isaiah. I guess I thought since they weren’t in the super-popular group but were kind of middle-of-the-road jock kids that I’d be safe with them. But they barely nodded when I said hello. Then, when our table was called, they got their lunches and never came back. I saw them find a table way over at the other end of the cafeteria. They weren’t at Julian’s table, but they were near him, like on the fringe of popularity. So anyway, I’d been ditched. I knew table switching was something that happened in the fifth grade, but I never thought it would happen to me.

It felt really awful being at the table by myself. I felt like everyone was watching me. It also made me feel like I had no friends. I decided to skip lunch and go read in the library.