Ah! Yes, I presume they are talking about fruit quality and have somehow tabulated the brix for fruits of various "qualities". I don't think it means much to us and would go by the average number. Again, this would be a pretty rough guide as to how sugars vary in different fruits. The dominant acid information is pretty nice to have. I also see they have a little information on tannins near the bottom.
I know that the apples I picked this year came in right about spot on with the Average value from this chart of around 13 brix.