Maximum weight of bathroom tiles

New to the DIY game, and I seem to have very rapidly forgotten some of my Properties of Materials lectures from my undergraduate.

What is the maximum weight tile that a I can risk sticking to my bathroom wall given the manufacturer’s data sheet specification of initial adhesion strength ≥ 1 N/mm2?

Intuitively, this should be independent of tile area because the tiles are all the same thickness, therefore "weightier" tiles have a larger surface area for which to stick.

Help much appreciated!!