The answer is that yes, they do. An actor coming over to make a film or perform in a play needs to get a work permit or a visa as an artist, depending on what they are going to be doing. It isn't always that easy - with a work permit, the producers of the film/play will have to establish that no EEA national can take this role. This is usually straight forward for mega stars, but not so easy for the guys in the B list. For example, earlier this week Harry Shearer, star of The Simpsons, had to pull out of a Radio 4 play as he has problems getting a work permit. There are often problems with footballers getting work permits, and a few years ago Mike Tyson was refused a visa to come to the UK for a fight.
My old firm did a work permit for a major US actress to come to perform in a West End play...and we didn't even get free tickets!!!
Lewinsky could have come over on a number of categories.
Vicky