Remove debris that's settled in the cracked inlay by brushing it out with a paintbrush.
Squeeze wood filler into the crack to form a single layer. Pack the crack with wood shavings to avoid having to fill the entire space with wood filler.
Apply another layer of wood filler on top of the wood shavings. Smooth it over the crack with a metal scraper, allowing the filled area to mound slightly over the level of the rest of table.
Allow the filler to air-dry overnight. Smooth the surface and bring it level with the rest of the table by sanding it with 100-grit sandpaper.
Remove dust from the wood surface by wiping the table with a dry cloth.
Brush a layer of shellac over the repaired area to provide a surface to which the wood finish can adhere. Allow the shellac to dry for five to seven hours.
Apply wood finish to the repaired area of the wood table inlay. Use several light coats to achieve a finish that matches the surrounding areas. Allow the finish to dry completely before using the table.