At least in Finland the 30 minutes is meant to be 30 minutes sitting down and eating your food. If your place of work has a shared cafeteria people are meant to eat lunch in, getting from your desk to the cafeteria and back, and queueing for your food aren’t meant to be part of the lunch break. Only the part you actually spend eating and thus properly on a break.

It’s a bit of a spirit of the law thing, though the law is quite exact on the matter. Good luck trying to find an employer outside desk jobs who actually abide by it, though, as factory jobs are scheduled around 20 or 30 minute breaks and if you’re not back at your line by then, production halts. Luckily that fact is typically compensated in the pay.

I’d assume other European countries with 30 minute lunch have a similar clause.