The Name Bank enables you to choose from a list of names for your characters. To access it, click Tools > Name Bank.
NOTE: The Name Bank function has been disabled from Mac Screenwriter 6 and 6.5. The name bank died when Apple removed support for the underlying technology from their OS a while ago. That said, the name bank is somewhat moot with the name generators available on the internet these days. Here are a few of them:
Tag: Movie Magic Screenwriter