As a training helper I have used a "table" once.....it was a Pit Bull and she was standing on a picnic table at the park.
. Other than that, no, never. Never felt the need to use one.
As a handler, I put one of my dogs on one because the helper just could not get what I wanted out of my dog. He was a real propponet of the table and considered himself to be quite an expert. I put the dog up there but the helper work sucked as bad with the dog four feet off the ground as it did with him standing on the grass, ( just as I knew it would). Took the dog back off thirty seconds later and back to my car.
I actually understand what Mrs K is trying to say but people are choosing to be offended by. lol. Some dogs don't really "need" to be worked on a table. Trainers choose to use it...fine....but that doesn't change reality.
As for the original question, as a helper, no, I don't work the dogs in "defense". I use many different ways to bring the dog into fight drive. When he wants to engage and fight with me, I reinforce that behavior. Doesn't matter if it is with his bark or his bite or what he is standing on.
As a handler, more and more I am tempted to try to use anything to get the right kind of helper work. However, just using tables, or anything else for that matter, will never take the place of a really talented helper. They don''t need props or tools as much as the people who really don't know as much as they think they do, believe.
Oh and yes, I do understand the concept of the table.