I use these to remove white water marks. I don't think it will do anything about the black mark that is a distinct issue http://www.homedepot.com/p/Homax-Furniture-White-Ring-Remover-Cloth-2236/202698033?cm_mmc=Shopping|THD|G|0|G-BASE-PLA|&gclid=CNTu0vi12MwCFcRahgodveABjg&gclsrc=aw.ds

It looks like there is a bit of black staining there, unfortunately;that is pernicious. Only thing that takes the black stain out is a plane or wood bleach.

Casey

I had a stain like that on an 8" wide, flat wood railing once. I did try oxalic acid to bleach out the stain, but it couldn't make it disappear. The same with a water stain I once had on an oak parquet floor. The only thing that worked was heavy-duty sanding and refinishing. And if you don't sand the whole top of a tabletop before refinishing, the patch will be very obvious.

I think we are going to try to sand the entire top down n see what's what, gave me an excuse to get a new sander. As for the curse of the black spots...fingers crossed

I've seen worse black spotting than what you have, so, hopefully, you may not have to go very deep. Good luck. I'd like to hear back when you are done.

I'll post results and methods which ever way it turns out

just be sure it's not veneer before you lay into it with a sander.

I had surprisingly good luck getting a very large and deep black stain out some oak, using the two part wood bleach sold by Kleen Strip, which I have come to learn is now discontinued. I had to treat the entire surface, because spot-treating leaves a ring, and lightens all the wood. But that can be corrected with the proper staining techniques and materials. Maybe you can find some old stock on the shelves of your mom&pop hardware store. Don't risk it on veneer.

Casey