It's funny, when we have free time at home, I don't say that E plays. Instead I say he's hard at work. He never stops moving, and is always on a mission. I'm not sure where the mission comes from, or why he's doing what he's doing, but he's very determined.
First he may come down stairs and go to his table and chairs, where all of his books are displayed. Very purposefully, one at a time, he must take every book off the table and put them on the floor. Once they're on the floor he'll ignore them for the rest of the day, but if you try and put a book back on the table, it must immediately be taken off again.