I tripped the waiter after I had finished dinner and found it funny
Why do you have to have bad manners to the waiter?
I mentioned about the waiter being so slow in bringing my checked plate to me.
But that doesn't warrant causing a scene around the whole restaurant and harming him and others around him. You are an evil person for tripping someone innocent, and you are liable for all the damages that you have done to him.
They were a bunch of unhappy people and they wanted me to care about their treatment.
That still doesn't mean you were allowed to hurt this person and treat them this way. There are better ways to deal with this, by calling over another waiter or asking for the manager, without hurting anyone.