The Lego table goes awesome! Uses 4 IKEA's TROFAST frames. 4 feet x 6 feet table top. Legos are organized by color in the bins. I'd make the overhang a little larger so chairs can scoot right up to the table.
Creative Ideas - How to Transform An IKEA Table Into A LEGO Table
DIY Lego table using Ikea Trofast storage system. On the top get a piece of wood or something for students to write on and then turn over to use Lego table. Then in the bottom put Legos in one, paper in other, crayons, etc.
An Ikea Hack custom train and activity table with TONS of storage. This is such an an EASY DIY project and a great way to get all of those toys up off the floor and organized once and for all! Maybe a Lego table and storage?