[Fern]

I could sort of see why they may charge more if you drink at a table as
opposed to the bar, since you'd be taking up table space that would
otherwise be more lucrative for the owner if someone were sitting at the
table eating a meal.

In my case, the restaurant has just one small seating area with tables
with no bar. We also have chinese restaurants in the area that serve
buffet style and they charge for more the same buffet on the weekend as
opposed to weekdays. It seems it's the chinese restaurants that want to
charge a la carte for every little thing.