Can I eat earlier if I have kids?

Yes, many casual 'cervecerías' and tourist-focused spots open kitchens earlier, but you will miss the local social vibe.

Do I tip if the meal is served so late?

Tipping is not mandatory. Rounding up to the nearest Euro or leaving a small handful of change is plenty.

Mastering the Spanish Daily Clock

In Spain, you must shift your schedule forward by two to three hours compared to most of Europe or North America. Aim for lunch between 2:00 PM and 3:30 PM, and do not expect dinner service to begin before 8:30 PM, with 9:30 PM being the local standard.

Adjust to the 'Merienda'. Because lunch is late and dinner is even later, eat a light snack around 5:00 PM or 6:00 PM. A small pastry or a coffee and toast will bridge the gap so you aren't starving before the kitchens open at 8:30 PM.
Respect the 'Siesta' window. Between 2:30 PM and 5:00 PM, many shops and smaller museums close. Plan your museum visits for the morning and use this time for your long, multi-course lunch.
Identify kitchen hours. Never show up at a restaurant at 7:00 PM for dinner. Most kitchens are strictly closed between 4:00 PM and 8:00 PM. Use this time for 'tapeo' (bar-hopping for small bites) rather than a sit-down meal.
Book your table for the right slot. If you want the authentic atmosphere, book your dinner reservation for 9:30 PM. Reserving at 8:00 PM often means you will be the only person in the restaurant, and the service will feel rushed.

Can I eat earlier if I have kids?: Yes, many casual 'cervecerías' and tourist-focused spots open kitchens earlier, but you will miss the local social vibe.
Do I tip if the meal is served so late?: Tipping is not mandatory. Rounding up to the nearest Euro or leaving a small handful of change is plenty.