Dry wood is like a paper towel and would soak up whatever you put on it. We treat wood to seal the surface and make it less absorbent so that it can be used without worrying. 

We can treat wood with oils or waxes. Waxes remains on the surface whereas oils penetrate deeper. Oils can also be separated into those which cure and those which stay liquid (like mineral oils). The ones which cure are best because a cured oil protects the wood better, waterproofing the surface and not washing out. Warm oil tends to penetrate the wood better. The oil comes in a bottle and you can put this bottle in hot water to warm up, than pour it onto the wood and wipe around with a piece of paper towel, allow it to soak in then wipe off any excess with clean kitchen paper.

The three common oils that cure are tung, linseed and walnut oil. Linseed and walnut oil have also been used as the carrier oil in oil paintings and it is the oil curing which cure the paint. Like painting canvas also dry wood soaks oil up and with some time it cures and no further treatment is necessary. All of my wood creations are already treated with tung oil. 

If you want to keep your bowls looking shiny and fresh then an

occasional wipe with tung, linseed or walnut oil will do the job.