It's hard to see but I believe you have both switches in the 150V-8A position. If so, then the scale factor is 4 (meaning the power is 4 times the reading on the meter, and the full scale is 4 x 150 or 600W). Thus a reading of 30 would mean a power of 120W.
It would seem that to operate, both meter knobs are set for the maximum voltage and maximum current of the circuit. Then you look at the table to see the scale factor for the setting. The 150V full-scale factors are on the left and the 300V full-scale factors are on the right.