Timing in public speaking is one of the most important aspects of humor and NO ZZZZZs speaking. Not only is timing involved in an individual piece of humor, it is also involved in the placement of that piece of humor in the overall presentation. Timing is also involved in spontaneous reactions to 'expected' unexpected developments during the presentation.
Jack Benny said, 'When you are speaking, timing is not so much knowing when to speak, but knowing when to pause.' He should know, because he delivered one of the funniest and most famous lines in the history of comedy after an extremely long pause. He was being held up by a robber at gunpoint. The robber said, 'Your money or your life!' Jack didn't speak a word for an extended period of time. The robber became impatient and said, 'YOUR MONEY OR YOUR LIFE!!' Jack finally replied, 'I'm thinking.' His persona as a cheapskate, coupled with a long pause indicating he was having trouble deciding whether to give up his money, or die was hilarious. A pause lets the audience catch up and draw pictures in their mind. It is the audience's signal to imagine.
In public joke telling, a pause just before and just after your punch line gives the audience a chance to laugh. Absolutely do not continue speaking when laughter is expected. Laughter is hard to get and easy to discourage. Hold eye contact a little bit longer than you think you should when delivering punch lines because time is hard to judge when you are pumped-up for a speaking engagement.
The size of your audience will affect your timing. Your presentation will take less time to deliver to smaller audiences. Smaller audiences should mean quicker laughter. Conversely, presentations will take longer for big crowds in large public arenas. Your pauses will be longer to compensate for the wave effect created because of the physical distance between you and the back row of the audience.