I had that happen when my mother set her hot tea cup on my dining room wood table. The heat penetrates the surface of the shine finish, very, very hard to remove without a professional to do it, but there are some things you can try. Google search and get the ideas. Some say to rub white toothpaste into the area, although it didn't work for me.
By
10/13/2011
We have had this happen a number of times with our table. We think it's the wood polish we use turning white because it's just on the surface. Usually we just used the green side of a scrubby sponge and a little elbow grease. Obviously, you don't want to damage the finish on your table, but use a little pressure when you scrub and you should see it come right off.