How high above a table to you hang a swag light?

At whatever height you desire. I don't believe there is a code dictating the height of lighting fixtures hung above a table.

Lighting heights are questionable when it comes to what someone likes.The rule of thumb for fixtures or chandeliers over a table is a minimum of 36''. Work from that height to start with.

Both replies are correct.
The rule of thumb is 30"-36" above the table to the bottom of the fixture.