cartouche vs memorial tablet

cartouche

noun
  • A paper cartridge. 

  • A wooden case filled with balls, to be shot from a cannon. 

  • A gunner's bag for ammunition. 

  • A military pass for a soldier on furlough. 

  • An ornamental figure, often on an oval shield. 

  • An oval figure containing the characters of an important personal name, such as that of royal or divine people. 

memorial tablet

How often have the words cartouche and memorial tablet occurred in a corpus of books? (source: Google Ngram Viewer )