I’ve done a few of these, on a number of occasions. It just seemed the right thing and that it is helpful. Turns out stacking the dishes or pushing them away just makes it harder for your server to clear the table or booth. Read up and enjoy your weekend out. DO remember to tip these folks, as many still work only for those tips! Your complete list of NOT TO DOs are here.
The real question actually is, ‘Coke, is it kosher?’. The article from Reader’s DIgest goes into the topic and just how Coke handles this, mostly during Passover as actually Coke is kosher all year round. Details, details, but you will see other links on this favorite product, brand. Read all about it.