I made this train/activity table for my niece's 2nd birthday. I did omit the bottom shelf to allow more leg room when sitting/kneeling on the floor. The one BIG issue I encountered was that I cut the top inset to fit perfectly. Then I painted it.... the pieces no longer fit due to the extra paint thickness. UGGGGG! So, I had to go back to sanding to get that nice fit again.
I put in a scrap of indoor/outdoor carpeting for "grass" for the train set to sit on. This is not glued in, so it can be removed if they decide to use it for something other than the train. I painted it using cabinet paint to give it a little extra protection against scratches and scuffs since it will be used by a two year old. I painted the inset white on one side, but I put chalkboard paint on the other side. This way, it's like three tables in one! An activity table, chalkboard table, and a train table! She loves it!
I need to get a picture of it with the top on so you can see the white and chalkboard sides. It was a really fun build!
I may build the smaller Lego version for my own house - not to play with Legos, but to keep the dog's tail from knocking over any beverages I set down! It also would be a nice place to store the laptop when not in use.