The Dice Roller plugin can do this. If you had a page with different quotes, where each quote was a block, e.g.:
Quotes.md
This is quote one.
This is quote two.
This is quote three.
…then you can use Dice Roller to display a random block from your quotes page:
MyPage.md (edit)
`dice: [[Quotes]]`
MyPage.md (preview)
This is quote two.