Heat the wax stick over a candle flame until it begins to drip. Drip the wax into the scratch. Use enough wax so it protrudes slightly above the scratch.
Hold a small metal spatula or metal putty knife over the candle flame until it is hot. Work the wax into the scratch with the spatula, reheating as necessary. Avoid touching the unblemished wood surface with the hot spatula.
Scrape the excess wax off the table with a credit card or plastic scraper. Scrape until the wax is flush with the surrounding tabletop.
Paint over the repair with a thin coat of clear shellac. Allow the shellac to dry completely.
Apply a single, thin coating of clear lacquer or varnish, depending on which was used originally to seal the tabletop. Allow the varnish or lacquer to dry for at least 24 hours before you use the table.