I have a Janome table with a cut out for the machine to set into. It's about 45" side to side and 18" front to back. I bought it from my Janome dealer when I bought the machine. Here's a site that sells some but none are just like mine. Mine is closest to the second one on the page but the legs are different. I love mine.
http://www.tonyssewingmachine.com/sewing-cabinets/