He was using his body language and gesticulation to make a digresion and push the speach in a new direction for a brief amount of time. Digresion is commonly used in public speaking when one is giving and example, introducing new topic, bringin a guest in, and so on.
Comedic Relief
Capulet calls for a sword, but Lady Capulet's lines 'offer' him a crutch instead. This is used to show how old and incapable Capulet would be in a street brawl with much younger and stronger fighters. Capulet refers to Montague 'flourishing his blade in spite' of him, which shows that Montague is not taking part in the actual fight either, just waving his sword around. This shows that the head of both houses are not actually effectual within the fight, but encourage its continuation regardless.
Jonathan Swift uses A. optimistic to F. to remind people of their childhood. The fact that he doesn't have any children made him eligible from his proposal.