I have done this myself using Minwax products with excellent results. If you want to keep the same color, you can use the CLEAR polyurethane coatings, in a variety of finishes. If you want a slightly darker color, you can use the polyshade, with a brush.
All of this assumes you have a wood stained table, and want a new finish. If you want a colored (like paint) finish, I cannot help you.
BTW the polyurethane finishes are quite good, and resist water stains, etc.
Hope this helps.