Each guest has a small dish with a delicate cone of slightly hardened salt by their plate. When they want some salt, they pinch some off the cone and rub it between their fingers, sprinkling it on their food.
I've experienced this at several of the nicer restaurants in San Francisco, and wanted to try it for myself. Here are the results of my experiments.
Step 1: Materials
a cup of Kosher salt - you should use a salt with course grains, but not too heavy
CLEAN paper - this will be in contact with one of your condiments
tape - to hold the paper in a cone shape
cups, spoons for mixing and holding
a microwave - to dry these out