Put a different colored dot on each desk in a group. When you need to have one student from each table do something, you can just simply say "Green dots, come get the papers for your table." or "Orange dots, take your table's trash to the trashcan."
This is a guide to organizing your classroom. A well organized classroom not only looks tidy and professional but also teaches your students basic organization skills. Having an organized classroom is key to having a successful school year.