I agree that body weight and backpacking style are two major variables, and your table highlights this quite well. However, height and obesity also significantly affect the equation and your table doesn't really incorporate that.

However, I'd also suggest that your actual body weight versus your "ideal" body weight factors in (You give this a passing glance following the table, when you mention "reasonably fit" hikers.)

Let's take two examples for a 5'11" hiker; one weighs 220 pounds, the other weighs 170. (Yes, these examples are me, before and after receiving a Type 2 diabetes diagnosis. At 220 pounds, I fit into the obese category; after losing 50 pounds and getting more active, I fit the "normal" range.)

According to your chart for "moderate," the obese me can carry a 38-pound pack; the healthy me can only carry a 29-pound pack. I'd suggest that isn't realistic - at least not with the same comfort level.

I would suggest that you modify the instructions for using the chart as follows:

1) Determine your weight using your "normal" or "healthy" BMI upper limit for your height (there's a calculator for this on the CDC website.)

2) Determine your typical packing method (Ultra-heavy to Extremely Ultralight.) Use your chart to get the maximum load in a given category for your normal weight.

3) Subtract a pound from that maximum load for every pound you are overweight to get to the total pack weight you can actually carry. (In my example, my normal weight is 170 pounds, so I can carry 58 pounds of pack weight. When I was 50 pounds overweight, I should carry no more than 58-50=8 pounds. I know from experience that carrying a 20-pound pack when I was 220 was exhausting after an hour or so; the same pack at 170 pounds is very comfortable all day and well within my capabilities.