Why Microfiber and Nothing Else
Paper towels feel soft and are not. Wood pulp fibers are stiff enough to leave fine scratches across a varnish, and those scratches accumulate into the dull patch that appears on a table after a few years.
Microfiber lifts dust rather than pushing it around, which matters because most surface scratching is caused by grit being dragged across the finish rather than by anything dramatic.
The limit is water. Damp is right and wet is not, so wring the cloth out and dry the surface behind you.
If You Want More Shine
A wood-specific polish used occasionally is fine and we recommend Guardsman products, which are made for real wood.
Use it when you want the surface to look its best rather than as part of the routine. The finish does not need it and nothing deteriorates if you never buy any.
The limit is what you reach for. Most supermarket furniture polish contains silicone, and silicone ruins more finishes than every other cause put together.
Spills, Heat and Pens
Wipe spills straight away. Standing liquid is the one everyday event that can get through a varnish, and the window is minutes rather than hours.
Use placemats and trivets without exception. Hot cookware set directly on a table can mark the finish permanently, and a trivet costs nothing against a tabletop.
The limit is writing. Put something under the paper, because a pen pressed through a single sheet dents softer species. Quartersawn white oak may show nothing at all while brown maple, hardwood though it is, takes the impression.