How to Read Motor Performance Chart/Sheet?

The graphics display on CR4 tends toward grayed-out images with tiny text and numbers, so the curves are unreadable. Power = constant x torque x rpm, where "constant" depends on the chosen measurement units. The efficiency of 40-45% seems awfully low, although it is possible.

Yup!! Actually the efficiency will increase if demand for power putput increases acc. to graph!! sounds weird!!

Is it possible!?!?

Generally, yes. (There may be exceptions toward the extremes of the graph.)

At lesser loadings, a larger fraction of total power goes toward fixed losses in the motor; hence the less efficiency overall.

Did you mean Leeson?