Yes, sure. No problem.
You probably noted these are the details for a particular last/width combination you didn't mention. Let's call this the target. The question is what can be said about the fit of the target for a particular size, given your ratings and the data from other members?
The answer thus uses your ratings (table 1), and comparisons extracted from the ratings of others (table 2). In other words, table 2 lists the comparisons from other members about AE's 1-511 last in C to the target (line 1), and from Alden's Leydon last in D to the target (line 2).
It's probably easier to understand when you imaging both tables merged into one. It's not always possible, but it works in your case. Then, it reads:
1. Based on your first rating and the first comparison, the target's fit in 7.5 (your rated size of 8.5 plus the size difference of -1) is estimated to be 3 stars (your 4 stars plus the rating difference of -1)
2. Based on your second rating and the second comparison, the target's fit in 7.5 (your rated size of 8.5 plus the size difference of -1) is estimated to be 0 stars (your 2 stars plus the rating difference of -2).
Since both estimations are for the same size, an weighted average is used to combine both. In your case, this is (3 + 0) / 2 = 1.5. In other words, the target in 7.5 (UK I presume) is unlikely to fit well according to the existing data.
To be fair, however, it should be noted that the method is likely to produce false negatives (lasts may fit well although they are estimated not to do so). The advantage is that false positives are relatively rare (lasts that do not fit well although they are estimated to do so).
If you have no other information, and you really want a shoe on the target last, you may want to ignore the second line. Then, the estimated fit for the 7.5 size would be 3 stars and this may be good enough for you.
Hopefully, this helps. If not, please let me know and I'll try once more.