A friend in Spain told me that she attended a dinner with friends from elementary school. Somehow, phone calls to one person led to another and soon, with some help from Facebook, they had reached 30. Many of them she hadn't seen since she was 12 years old. Because it was the weekend around Christmas, most were traveling back to their home town to visit family anyhow. It wasn't a get-together with spouses and families. It wasn't a big catered party. Just a dinner in a restaurant that could accommodate a table or two for 30 kids who happened to have become forty years old. She had a terrific time.
If this had taken place in the U.S., rather than Spain, I imagine the group of 30 would probably have had an "organizer" who'd have arranged a catered buffet. They would have hired a band, or at least a DJ, because what's a party without dancing? And to make sure we all remember each others' names, we'd have name-tags set out in alphabetical order on a table with a white tablecloth in the entrance room, and one of the 30 would have volunteered to greet the guests and help them find their name tag.
The more low-key Spanish don't do this kind of thing. They can't compete with us in the world of production and marketing. They decide on a restaurant, and make sure everyone has the address. At the end of the night, there's no one to congratulate on the fine party. They've simply shared a dinner with friends from the past.
I'm sure that somewhere in Spain someone has catered a get-together of school buddies, and made a big production out of it. But in general, it's not their type of thing. It's our type of thing.