In my experience with plasma cutting the water table (as in water level) sits just above the torch tip. This is a nicely constructed cutting bed with a bucket of water under it.

At the Sheet Metal Local 88 JATC in Las Vegas, Nevada, a new dual plasma cutter table from Production Products, Inc. will enable sheet metal apprentices to practice duct fabrication and beyond. The ...

For instance, LubeCorp, a Canadian company, offers fluid for treatment of the water on plasma cutting tables. The main objective of this fluid is to prevent the formation of rust and corrosion.