jtaylor wrote:

Some of these tables are advertised to have a method by which the table can
be decoupled from the gear, to allow quick rotation without turning the
worm. I have been turning this picture around and around in my head and
cannot figure out how they do this.

Someone tell me or point to a drawing, please...

Mount the worm shaft in an eccentric bushing, rotate bushing, disengage
worm.

Rich