We've discussed this a bit before,
here, but here's a quick summary.
Sometimes they have tables/chairs set up, and sometimes they don't. When it's a seated show, there will be a $10 minimum per person charge to sit at the table. I found the food to be pricey and not terribly vegetarian/vegan-friendly (it's soul food, after all), but I was able to manage by getting a salad and having them not put in the hardboiled egg.
It's not always obvious from their web site which seating/standing configuration they'll have-- sometimes the event page says "standing room only", but the Lemonheads show doesn't have that text. Bottom line: go early for the best seats, and be prepared to spend $$ on food/beverage on top of the ticket price.