What if there are pillars in the middle of the wedding hall?

Ask the hotel, refer to how the wedding banquet was handled before, at least know what it is. If you don't deal with most of them, you can do the same.

If the budget is enough, decorate the pillars. Curtains, wisteria, KT board design, lanterns and so on can be used.

If the budget is sufficient, you can consider floral modeling.

The above is just a personal opinion, I hope it will help you.