A chalkboard table is a relatively inexpensive toy you can make for your kids (and don't forget you can make your own chalk too, to save on money!) Why spend crazy money for these in fancy kid stores when you can make your own for next to nothing.
First, hunt around and garage sales or thrift stores for a child size wooden table. Sand down the table first if needed and paint or spraypaint it with 2 or so coats of black paint. Once dry, then use chalkboard spray paint for the final coat. You can also coat the legs and sides with chalkboard spray paint to maximize the chalk area for your budding artists.
Can't find a wooden table? You can also attach a plywood top to a plastic table or card table, then use the painting steps above. Just make sure there are no sharp corners or splinters that your little ones could get injured on.