Hi, I was wondering if there is a way to stop the click sound every time the switch goes on and off.
Also, is it possible to connect more than one output device at the N/O, COM, N/C outputs?
No, you can’t stop the ‘click’ sound from a relay, otherwis he doesn’t work 
You can connect a max load of 3A (at 0…240V), this can only one device or more (ex. 5 lamps).
Since this relay is marked for 3A at 240V AC, it should be able to take a load of up to 720W.
I would mark that down to 600W just for safety. Therefore if you are connecting 60W bulbs to it, you can connect up to 10; or 6 100W bulbs.