I was talking to a friend who suggested that I take my newly constructed
tabletop to the services of a local woodshop for final planing. The logic
being that they are equipped to handle objects far far wider than anything I
could have as a woodworker and passing my tabletop through the planer one
more time would absolutely ensure the tabletop was flat, planar, and
minimize any finishing that I would have to do.

Does that seem like decent advice, or are you all thinking "why isn't the
finished tabletop perfectly flat to begin with?"

Just for reference the tabletop is created from 4 10" wide pieces and sad to
say as this was my first attempt it didn't turn out as well as I expected.
It looks as though the finished wood bowed slightly after I had finished
it - I'm wondering if the weather changes may have something to do with
that? It is for all intents and purposes fall where I live now.