Deciphering an Asian Bladder Pressure Tank + Pump
That label describes the motor specifications, not the pressure tank.
Single Phase, 220 Volt 50 hertz, 1/2 horsepower (.5 HP), 2850 Revolutions Per Minute (RPM), Continuous Service (SERV C), Suction 9 (possibly BARS).

I'm not sure what the other abbreviations are, but they could be related to the pressure tank.

Most pressure tanks work based on what you want your target pressure to be.

In english, my large 80 gallon pressure tank keeps my household water pressure around 60PSI (~4 BARS). In most cases, the bladder in this tank would probably be set to a similar pressure (size of the tank shouldn't matter, pressure is pressure).

Your tank looks a little small for a water heater supplying a shower or something using a similar volume, so you can expect it to cycle more often, and in fact, because of the CONTINUOUS rating, it's probably designed that way for on-demand pressure.