“Does this mean that the maximum speed of my line is 36 Mbits/sec for download and 11 Mbits/sec for upload?”
that’s correct
What DSL device do you have (Netopia/Centro grande/Internet-box?)
"On the other hand, I don’t understand the dB measurements below (“line attenuation” and “Signal-to-noise ratio”)"
Unless I’m mistaken,
it is the quality of the connection and distance to the DSLAM as well as the possible performance.
“Otherwise, if you want to look at the maximum capacity of a line for a future apartment when moving, you have to use the link I gave.”
This is also correct but it can be better or worse than what the checker will announce once there.