I have a pre-1990 Mayline Ranger Drafting Table, with a mystery finish, under the rubber mat. It's soft and sort of sticky in places. It appears thicker in some spots too. Some of it comes off easily with a razor blade, but in other places, I'm hard pressed to remove it, without gouging the top.
I started with adhesive removers, with limited success. CitruStrip AR seemed to soften it up, if I left it on for a while, but it didn't get it all. Acetone, GooGone, etc. did nothing.
I haven't tried paint strippers yet; want to make sure it's not spray on glue first. I'm guessing some kind of poly, or maybe even shellac.
My other Ranger tables appeared to have the same finish as well, but I had removed the rubber tops on those many years ago, and the finish underneath, looked like an evenly distributed light matte urethane. Care instructions offer little beyond the typical, "damp warm cloth", boiler plate spiel...
No chemicals were used on the section in the picture/video. I plan to cover it with a large anti-static mat once it's cleaned up.
This top was stored in an uninsulated/unventilated Midwestern garage, for the last 4 to 5 years, with the original rubber mat still in place. I'm wondering if that could have made the finish soften up, and could also help identify the type of finish.
YouTube Video of Scraping Finish "I gouged the top a bit".