The next sentence: ¿Cuál es el menú del día, por favor?
The waiter tells you there are jellyfish today that hand out mild electric shocks while you eat them (cuál es el – the German “Qualle” means “jellyfish”, “elektrisch” “electric”) – but the guests say it was the best menu ever (menú). One guest found the shock so strong that he punched a dent into the table, and the waiter even took a slide of it (del día – the German “Delle” means “dent”, “Dia” means “slide”).