Here's the "light table" I use to trace my patterns onto fabric for redwork. It's homemade - just a piece of Plexiglas and one of those lights you mount under a cabinet. I started using it about 10 years ago for calligraphy, and what I like best about it is that I can adjust the angle to suit me as I go along. The board rests in my lap (it's not heavy), and I can move it a little or a lot as I trace a pattern. It measures 19 by 24 inches. I got it at a hardware store and it must have come pre-cut because I would never ask for those measurements! The light rests on my desk top (it's not hot), and the bulb seems to never burn out!
When not in use, I store the Plexiglas under the desk and the light on a shelf behind my desk. (It stays plugged in.)
Front view - from over my chair
Back view - so you can see the light fixture better. It measures 12.5 inches long.