Non-sealed wood table

Mineral spirits and a light sanding using 220 grit. Always sand with the grain and use a sanding block. Be extra careful about the edges. How you protect it depends on how the table is used. You have the option of applying a stain. Shellac, varnish, tung oil, Danish oil, paint, lacquer are various choices (let me know details and I'll make a recommendation here). After the finish is applied, wait a month or so to cure, then polish with a wax.

Do you want to seal it? If so, polyurethan is the least maintenance after the job. Tung oil is really nice, but needs to reapplied every year or so. What are you using the table for? Dining, woodworking, what?? That will determine whether you should even seal it.