watermarks

[jbuttress23]

repair polished table top from watermarks

[Zacs-Master]

Oh go on then, I'm at a loose end anyway.

[RATTER15]

I'll give it a go if Zac cant manage the job.

[follyfancier]

cut a shelled brazil nut in half and rub over the white marks

[Essell]

Depends what sort of finish the table has. If it is French polish it will be difficult and I don't know the answer. If it is a stain I don't know the answer.
If it is the mellow finish of, say, a well polished refectory table it is much easier. Take some fine wire wool and lots of water and rub hard all over the top. When it is dry, rub in a mix of olive oil and lemon juice (or vinegar), let it dry out for a couple of days, then polish as usual. The finish will be very slightly different. I know it works because I did it to a badly watermarked table I bought years ago.