They are names of characters from the film Snatch, Sabrina.
I and the rest of our fosterers tend to pick names that follow themes. We've had pairs of kittens called Bangkok and Hilton, Marmite and Toast, Holmes and Watson. Caroline had a litter last year called Maltezer, Snickers, Flake, Mars and Bounty. At the moment Caroline has three boy kittens called Norman, Stanley and Fletcher.
All the strays we took in over Christmas had boozey names - Lanson, Champers, Moet, Bubbles and Bolinger.