If you didn't start out your year (all grade levels) discussing bucket filling, go back. it's not too late! For great anchor chart activity to go with the book: Have You Filled a Bucket Today? Teach your students compassion and empathy.
Use colored dots to make groups easy. Put a different colored dot on each desk in a group. When you need to have a student from each table do something, you can simply ask for all the green dots to bring you the papers from their group.