We have three nested tables that are stained reddish brown.
They don't have any type of lacquer finish on them. Our
grandmother has kept them for many years without this problem.
The problem is that, since the tables were handed down to
us, water condensations from the cold soda cup leaves a pool
of water, washing away the paint. This is seen by the white
circular marks on the table.What is a practical solution to
solve and prevent this problem?

Thanks