This waitress is demonstrating the standard procedure for when they get intercepted by a patron while bringing food to the table. The moment they get held up by any patron for whatever reason, they will signal another waitress to take the tray off their hands so that they can focus on serving the patron(s) currently immobilizing them. This way, food will still arrive fresh at the designated table within the allocated time!
Although, during busy seasons, they would still get overwhelmed. But since they provide such good service, the patrons don't really mind any food taking longer to arrive at their table.