Titles.

[Kay]

Slapper and Tart,How did these names come about? Does anyone know if they're old slang? T,I A.

[Quizmonster]

As long ago as the 1700s, the word 'slapper' was applied to a big, strapping woman. Since then, it seems to have taken on the meaning of a promiscuous one instead.
'Tart' has had the promiscuous sense since the 1880s, though it was affectionate slang - especially in Australia and New Zealand - before then for a girlfriend, with no suggestion of moral laxity. That is, she was something tasty that one was fond of just as one might like a tart in the sense of a cake sort of thing.

[felinechums]

I always thought the word slapper was onomatopaeic (hope I spelled that correctly)