This finish is most like wood in its natural state, allowing the full beauty of the grain to come through. Oiling doesn’t provide a full seal though so spillages should be wiped up immediately. It is a good idea to re-oil pieces when they are delivered to your home to replenish the finish and give your pieces a good start in their new location. The oil can be used to replenish the protection and patina. For most homes, oiling every 3-6 months for the first few years should be sufficient. For very dry centrally heated rooms or conservatories re-oiling might be needed more frequently. If this finish gets marked it can be sanded and re-oiled. Some temporary colour difference might be noticed but that should right itself with exposure to air and light.