When I was i the home repair/handyman business I got on to the Durham's Wood Putty from a friend who was a carpet layer and tile setter. We used it for minor floor and counter leveling to get a smooth surface.
WARNING...about Durham's!
It sets up quickly so do not mix more than you can use in just a few minutes.
Don't use too much water or it will be weak and take a long time to 'set'.
If there are indentations left you can go back and re-fill later to smooth it out.
It is much LESS forgiving than 'spackle' or dry-wall compound.
Dries fairly quickly and hard as rock so mix in a paper or plastic 'throw-away' cup.
Sands just like wood.
~~~GrayBeard~~~
Great stuff for filling cracks, holes and for places where you have to later insert screws. Drill pilot hole just to fit the screw.