and so on vs whatnot

and so on

phrase
  • Used to indicate that a list continues in a similar manner. 

whatnot

noun
  • Other related objects or ideas. 

  • A freestanding set of shelves on which ornaments are displayed; an etagere. 

  • A small unspecified object; bric-a-brac (in plural) 

How often have the words and so on and whatnot occurred in a corpus of books? (source: Google Ngram Viewer )