How do I determine my breaker panel's maximum wattage?
OK, I am not 100% percent sure of this, but what I understand from the labeling on one hand fits in with what I know of electricity on the other. So, let's say 98% sure.

40A : this is the circuit breaker itself, standard three-phase AC.

50A : this looks to be a residual current breaker, rated 30 mA. 

So:


If something in your house has a short circuit between live and neutral and starts sparking, the 40A breaker should trip protecting you from starting a fire. 40A is the maximum draw you have.
If, on the other hand, you have a short circuit to earth -such as live current getting in contact with an appliance's external surface- then the residual current breaker cuts in.


The residual current is there mostly to protect the user from becoming the shortest path to earth, or in other words getting electrocuted. This is why it needs to be at a very low differential rating of 30 mA. It also makes sense that it has a higher current rating (50A) than the main breaker, since we want to make sure the main breaker trips before the residual current breaker gets damaged.

To complete the individual circuit identification:

(4) is for the washing machine

(5) is for the fridge

The other circuits are as the OP indicates.

To answer to original question: 40A x 110V gives you 4400 VA. Since this seems to be a 3-phase + 1 neutral setup, you will in reality have three times the current, 40A on each phase. So, in total 13200 VA.

This is not quite the same in Watts, but with a hypothetic cos(phi) value of 0.95 you should be good for some 12000+ W. You should be OK with the devices you want to connect, as long as the circuits are well balanced (equal draw on each phase). I would suppose this is so -the installation looks really professional quality- and try it out before requesting changes, since adding more power will mean changing the main breaker and the residual current breaker (as well as paying a larger monthly charge).

Hope this helps.