A few year back, we bought our dining table at a home decor boutique that I worked with. It originally came with a wax top finish (different than the glossy finish on the chairs). We decided to strip off the wax finish and seal it with something different. Well, we must not have done our HW correctly, because it leaves horrible watermarks, and every time the table is wet, the stain would get on our clothes. Disaster!! For some silly reason we were just too lazy to bite the bullet and refinish the table. But now that we live in a house with a separate garage, we have no excuses. So, here is what we did:
First, sand that puppy down. We recently purchased an orbital sander, and can't believe we have gone through life without one!!! I DEFINITELY recommend it. It does a much better job and is way faster (and less tiresome on your arms!) than the old-school way.
Next, apply the stain of your choice. We used MinWax Dark Walnut stain, and applied 2 coats (waiting for it to dry in between). You can apply it with a white rag, but we used a paint brush.
Once that dried completely, we applied MinWax Clear Gloss Polyurethane. We applied 3 thick coats with a brush, allowing at least 4 hours in between each coat.