OK, so I know this really has nothing to do with subbing, but I had to share (and show off) my handy skills. I built this table and spent only $60! I am using it in my house as a craft table for my children, but I can see how this or a modified design could have a place in a classroom to house work stations.
I have to start off by crediting my inspiration. This is what I found that gave me the idea, then I changed the design based on materials I already had and what I found on sale. Designer Craft Table for $150
My materials were four Closetmaid shelving systems I purchased at Target for about $15 a piece. I already had a piece of 24" x 48" mdf left over from a project my husband did. You can easily purchase that, particle board, or solid wood from a home improvement store. You can choose the size based on your purpose. The 24" width is a pretty good one since shelving units come in that size, but it is not a big deal if your top overhangs a bit. I also used some semi-gloss interior paint I already had, but you will need to purchase that if you don't have any.
My first step was to paint the tabletop. Then I assembled the four shelving units according to their directions, putting two on each side for the table "legs." The last step was to affix the tabletop to the shelves using screws. The height ended up being slightly taller than a regular chair, but perfect for a couple of shorter barstools. Just pay attention to the measurements as you are choosing your materials to make sure they suit your purpose.
Yes, mine did not turn out as fancy as my inspiration, but you can add as much "fancy" as you choose. And I just love how functional it is!