It's a warming tray, circa 1970. I love this thing. It used to belong to my mom, but I don't remember her ever using it to warm food. I only remember using it to melt crayons onto paper, which I did often as a kid. When I was a teacher, I used to borrow it from Mom a couple of times a year for my students to use. Eventually, she must have gotten tired of me borrowing it so often and let me keep it.
I keep bags of broken, peeled crayons with the warmer. To use it, simply plug it in and wait about two minutes. It will get very warm, but not so hot that you can burn yourself unless you deliberately try. The first time Trevor used it at age 2, I put gloves on his hands so that if he touched the warm surface it wouldn't hurt him. I didn't bother with gloves once he turned 4 and his skin was less sensitive and he understood not to deliberately touch the surface.
Once the tray is warm, put a piece of paper on top and draw with the crayons. The wax goes on creamy smooth and acts almost like paint. You can swirl, blend and layer the colors. When you remove the paper, the wax is instantly dry.
Here's a stocking that Trevor made:
And here's mine:
I made this tree too:
We also made a bunch of ornament-shaped gift tags by melting stripes and globs of color on a sheet of paper then punching out circles.
Here is a small sampling of our tags. I made the three on the top and Trevor made the three on the bottom:
And here's a close-up. The 'hanger' is a rectangle of silver cardstock and a piece of silver thread, glued to the back of the circle.