What is N/mm² in block characteristics?
Presumably, being force per unit area it's compressive strength. Pounds per square inch in our non-metric units.
As such, under perfect conditions of perfectly even loading and adequate support, your 10x10cm brick would hold just over 10 metric tons. Given 10.5 metric tons, or any imperfection in how evenly the load was spread, it would crush.
So, that's an informative number, but not one you'd actually design to. It does tell you that these bricks are stronger than ones rated 8, and weaker than ones rated 12, but any of them you'd expect to design to a safe loading a signifcant factor less than that for a structure you wanted to stand up for a long time. One quick search finds a document claiming typical masonry safety factors range from 2.5-4, so you'd limit your actual compressive loading to between 4 and 2.5 metric tons on that brick. In most real-world applications, loading would be much less.