I built a DIY Lego tray table for my son's birthday that I converted into just a lego tray that turned out so much better and he loves it. For collaborations
DIY Lego Tray with Organizer - The Handyman's Daughter
DIY Portable Lego Tray Revised - Jaime Costiglio
Easy DIY Lego Tables Ikea Hack! Lego Desk Tutorial - Must Have Mom
DIY Travel LEGO Table Treasure Box - Best Handmade Gift for kids
DIY Travel LEGO Table Treasure Box - Best Handmade Gift for kids
List of supplies below: 7 hotwheels tracks Cardboard (10 x 25 inches)
LEGO Table from Two Tier End Table - The Kim Six Fix
DIY LEGO Tray Table - SO FUN! Lego storage diy, Lego tray, Lego organization
DIY LEGO® Tray Table
Easy IKEA hack: LEGO table & storage (folds up!)
DIY LEGO Travel Case Made from Lunch Box