For a fool proof and durable finish, I would suggest using a wiping
poly. Brush marks in Poly can be brutal. You can wiping poly pre-mixed
or mix your own from any oil based polyurethane by mixing it 1:1 with
mineral spirits. The can might say not to thin this much but it works
Wash it on thickly with a foam or bristle brush, then wipe it down with
a lightly saturated lint free cloth (tee shirt). Let dry at least 4,
preferably 24 hours between coats. Lightly hand sand with 400 after
first or second coat. 3 or 4 coats total will be plenty, more if you
want a flat plastic look. 48 hours after last coat, circular motion
with 0000 steel wool and very small amout of furniture paste wax, then
buff after dry (10-20 minutes).
It's best to really flood the surface, then wipe it down so you get
good saturation in the grain.
For a better look (IMHO), after the first or second coat, wipe it down
with a dark gel stain and the Oak grain lines will hold the dark stain
and really look great. Make sure to seal another coat or two over this.
Of course, try all of this first on some location where it is less
visible than on the top to make sure you like the look.