Slam Books are an evil thing, but so are many things that children partake in. Slam Books could come in many different forms, but the basics of it is that it acts like a forum board that you pass around. Typically you'd write one person's name at the top, and then you'd pass it around and say nasty things about them. You could also do different variations of it, but most people enjoyed the mean variation. What can I say? Kids are cruel.
I never got into Slam Books personally. I was genuinely afraid that anything I wrote would end up coming back to me. I didn't have the confidence to withstand a slam book in my name. Maybe there was one in my name, but I blocked it out of my memory because it was too painful. That's not unlikely.