4 Poured out their plenty without spite or spare:
spite > grudge, meanness spare > restraint, parsimony
5 Naught wanted there, that dainty was and rare;
Naught > Nothing at all [was] dainty > pleasing; scarce; choice; delicious rare > excellent, fine (the same phrase occurs at 108.50:9)
6 And ay the cups their banks did overflow,
ay > ever, always banks > [brims]
7 And ay between the cups she did prepare 8 Way to her love, and secret darts did throw;
darts > [glances]
9 But Britomart would not such guileful message know.
know > know; or, perhaps, considering 301.50:9: acknowledge, recognize (but cf. 301.53:9)