There isn't a direct verb equivalent to the adjective "affable." To express the idea of being affable, you can use verbs like:
* To be friendly
* To be approachable
* To be amiable
* To be congenial
* To be pleasant
* To be agreeable
For example, instead of saying "He affabled the guests," you could say:
* "He was friendly to the guests."
* "He made the guests feel welcome."
* "He greeted the guests with a smile."