It is really great that you decided to write.  Bullying has become such a huge problem and it sounds like your friend is causing some problems.  Good for you for noticing that this isn't right.

Usually a person that bullies does have something else going on at home or some feelings inside that are consuming them and they feel like the only way to deal with them is to cause issues with someone else.  Not wanting to stand for it anymore is understandable. 

Have you tried talking to him when he does trip you or slam your book?  Telling him that it's not cool or that he is being obnoxious when he does that may make him see what is really going on.  It sounds like he is really reaching for some attention and the book slamming and other stunts gives him some attention.   Whatever is going on at home with him probably is hurting him but what he is doing to you is not acceptable.

If you have a counselor at school that you can talk to about what is going on that would be great.  Talking to a parent or another trusted adult about what you have noticed and experienced will allow them to help you make the right choices and say the right things when you do talk one on one with this friend.  Maybe invite him over once more and have a heart to heart talk about how he treats you at school is embarrassing and not cool.  See if he makes a change.  He may think it's just funny, but it most definitely is not.

We hope it helps to talk and get this out.  We are here 24/7 and would like to hear how this turns out.  Keep us informed.

Take care,
Naina, counselor