Thanks for the further explanations. I do believe you've provided enough info to squash the bug.
It required a little fiddling, and it may affect some obscure scoring outcomes, but they should at least calculate properly.
The singlemost issue I believe was that the STEW AVERAGE function, initially used to generate the STEW QUALITY for the item description, relies on how many BOWLS OF STEW you have...but, let's say you submit all 8 STEWS to the BLACK TABLE, without ever "investigating" the average, your average would then be defined by a numeric 0 for STEWS IN INVENTORY. Basically a divide by zero error.
STEW AVERAGE now runs at BLACK TABLE SCORING and divides by [INACCESSIBLE], and I'd say works as one would expect. I will re-upload it imminently.
Thanks again, eagle-eyed HANDCASTLE.