blotter vs exercise book

blotter

noun
  • A register of the related events made in the form of the list of times and brief descriptions. 

  • A piece of blotting paper in a pad as a piece of desk furniture. 

  • A daily register of arrests and other events in a police station. 

  • A portion of blotter acid. 

exercise book

noun
  • A booklet for students, containing either problems and exercises, or blank (often lined) pages for writing answers. 

How often have the words blotter and exercise book occurred in a corpus of books? (source: Google Ngram Viewer )