Crack open a walnut to expose the "meat" inside. Rub the meat into a scratch, then lightly buff it with a soft rag -- the color bleeds into the scratched wood to stain it and make it less noticeable.
Color in slight scratches with a felt-tipped marker. If you don't have the right shade, you can purchase different colors of wood stain markers from a hardware store -- they are designed for this purpose.
Fill in shallow chips and dings with clear nail polish -- just a few drops do the trick. After it dries, sand it with 600-grit sandpaper to make it flush with the rest of the table.
Steep a bag of black tea in hot water. The longer you steep, the darker the water. When it reaches a shade comparable to that of your wood, dip a cotton swab into the solution and use it to stain scratches and gouges in the wood.
Stain wide gouges and chips with wood stain that matches your original finish.