You'll find that most unskilled jobs are better paid in Sweden. Working as a waiter might in fact be better in London, though, as people are more likely to give tips than in Sweden. Scandinavian workers have a reputation for being punctual and hard working, which may be helpful when applying. The restaurant/hotel trade probably have the most job opportunities. A relative of mine moved to London from Sweden last year, and got a job within 48 hours of arriving!
Try the EU job database for an idea of what's available.
Try the EU job database for an idea of what's available.