What does this even mean?

I'm a ninth grader and in my home class there is a boy who constantly tormented me. He would poke me really hard and punch me on the side of my waist. Once, when I was between tables that were in a U formation, he trapped me inside of them, and when he finally let me out, he said, "Like trapping a cow." I finally told a counselor about it and someone talked to him, but why did he even do that?