Yes and No.
If you want to know that your PC pulls twice as much power as your TV then you have a good meter. If you want to measure very accurately then you have a bad meter.
A watt meter is not simple.
Most low cost “watt meters” are actually current meters with watts written on the display. They assume the voltage is 115 volts. If you line voltage is high or low then the meter will be off.
Most meters do not account for poor power factor. With resistive loads the read good but with a PC they will read 25% off.
There is the old average verses RMS problem.
Some meters read (average voltage) X (average current). It is more accurate to measure (instantaneous voltage) X (instantaneous current) then average over time.
Your meter is far better than no meter but not as good as a $500 meter.