If you're going to pay by credit anyway, you can usually open a tab when you start, and then pay all at once at the end. That's how I've always done it, maybe it's regional?
The non-local places around the USA will take your card when starting a tab and many automatically add gratuity if you walk out without closing it (unsure if they place credit holds based on each order). At venues like concert arenas you may not see this, but I always suspected it was more due to the logistical challenge arising from people all wanting to leave at the same time.