I bought a very nice looking wood table off of a friend who was moving and had no need for it. It had a small white discoloration in the finish, but otherwise was just fine. I found the cause of the discoloration the first time I placed way too warm of a plate on it. The cheap finish discolored instantly. Surprisingly, wiping the burn mark with a furniture wipe actually removed the majority of the discoloration. To remove the deeper burns, rub the discolored area with very fine steel wool. Polish the area and wax the whole table once you are done.
