The best approach for furniture maintenance is prevention. Make sure to use a damp cloth to wipe away any spills easily. Take care not to scratch the surface of the wood if possible. It is best to use coasters and placemats as small profile ways of protecting your solid walnut furniture. Alternatively, you can use a tablecloth to cover the table completely. Most importantly, clean any spills immediately. Make sure to avoid using harsh chemicals and plain water when cleaning walnut. You can use furniture wax for safer upkeep.