Whats the maximum power in WATTS for this type of cable?
That load should be all right. The wire you named is considered good for 1920 watts continuously (3 hours or more at a time). This assumes 120 volt AC power as used in North America, Colombia,  parts of Ecuador and parts of Philippines.  

In other parts of the world that use 230V for power, the wire can carry even more watts. 

However the 1920 watts is for all loads drawing from that circuit   if you were to turn off the breaker, whatever else lost power is also on that circuit.