Wipe some mineral spirits on it and see what it looks like before you go fooling with stain.

If it looks good like that, you can just apply some brushing lacquer. Watco and Deft are two common brands. Lacquer is what is on there now if it's the factory finish and will bond perfectly with it. Believe it or not, not all clear finishes are poly just because that's what jams the shelves at the home centers.

If it does not look good wit the mineral spirits, get a chemical stripper and take it all off. Sanding off an old finish is a poor way to go. It will not get it all off and if the table top is veneer (and it looks like this is because of the different grain directions and edge banding), you risk sanding through the veneer and ruining it. Stripping is messy, but effective, less risky and it's over without gumming up 8 sheets of sandpaper.

But if it's ever had Pledge on it, it will likely "Fish-eye" The cure for this is to put on a coat or two of dewaxed shellac (SealCoat by Zinsser), then apply whatever finish you wish.

Thank you so much for the information, really appreciate it!