That is a nice chart and should be very handy. One thing i didn't notice on the chart was the "prop factor" description.

prop factor = diameter times 2 and add the pitch...for instance a 12x6 prop ...12 times 2 =24 plus pitch of 6 = 30.

12x6 = 30 pf
13x4= 30pf
11x8 = 30pf

All props with the same prop factor take basically the same horsepower to turn the same rpm (there are slight differences between manufacturers). Witht the props ive mentioned if you want a speed demon use the 11x8 or if you want a stump puller use the 13x4 the motor wont know the difference.

If you use this formula and use a prop factor from the recommended props from the manual you should always be in the ball park.