The classmates would then fill up the memory book with their names, address, phone numbers, hobbies, birth date, what they wanted to be when they grew up, their motto, their fave colour, etc. It could be as detailed, artistic, and colourful as they wanted it to be or it could be very plain and short (not too many details given). It was all up to the students themselves. The classmates could pick whichever page(s) they wanted to write down their details on, so one of the exciting things about getting the book back was to find out where he/she had written down their details on he he he...Another exciting thing was that if you had a crush on a boy, you could find out more about him after he filled in his details in your memory book HA HA HA HA HA...
So the book owner usually gave the book to her BFF(s) and seatmate first and then she'd hand it over to her other classmates. Ideally the classmates took it home with them and then return it to the owner within a day or two, though sometimes the boys would forget about it and the owner had to ask them to remember to bring it back. Some boys didn't even bother taking it home, so instead they fill it up during a break and returned it immediately to the owner.
I distributed this kind of memory book in Junior High and kept it for years, though my mom has burnt a lot of my stuff after I moved to Finland. I remember some of the more artistic classmates would doodle or draw some stuff on their page. I myself loved adding colours when I filled up someone else's memory book, so I'd usually use different pens to write down my details he he he he...I'm not sure who or how the whole thing started, but I kinda like the idea of having my classmates write their own details in a memory book. Different handwritings, different styles.
Have you ever had this kind of trend back in your days? For some reason, this trend stopped altogether in High School (nobody ever gave me any memory book by then).