“A Slam Book is a notebook (commonly the spiral-bound type) which is passed among Junior high school students. The keeper of the book starts by posing a question (which may be on any subject) and the book is then passed round for each contributor to fill in their own answer to the question”
Above quote is from Wikipedia.org on slam books. But slam books can use for other purpose also as well. A slam book can be used to share and exchange personal information (hobbies, feelings, likes, unlike, thoughts about friends etc) between new friends. And simply there is no age bar.
This post is on online slam books, online slam books can be used to make friends, share thoughts, and simply to become closer.