Armorer's tables, aka Workbenches, grant your gear 20% greater Armor for a limited duration. They can typically be found where there are blacksmiths or armorers, but the presence of these craftsmen is not strictly necessary. With the Hearts of Stone expansion, enchantments were introduced, among which is Preservation which makes the enhancement provided by armorers' tables permanent.
There is only one armorer's table, located inside the Nilfgaardian Garrison
There are 11 armorer's tables:
There are 8 armorer's tables:
There is only one armorer's table and it is inside the keep.