The data tabulated p19 doesn't have enough explanatory data to draw much in the way of discrete conclusions. However, the numbers trend in a manner one might expect to see.
Certainly, there is not enough data to draw any conclusions regarding specific performance as a function of bank angle
There is no explanation why there is an apparent preoccupation with 5 degrees bank at the climb speed. I'll see if I can find any OEM guidance on the subject. Certainly, I would have expected that the climb target would have required somewhat lesser bank.
What the data do suggest, however, is the folly of homegrown reduced thrust takeoffs (presumably) driven by engine cost considerations but without any thought to weight reductions appropriate to maintaining OEI performance margins.