It's the whole of Book I, in the 1715 Hughes edition of the poetical works.  No written annotations, but there are many under-linings and bracketings of lines and whole stanzas which are themselves fascinating to contemplate, just to think of Keats's eye (and ear) taking them in, taking lessons from them.  I suspect other books have similar marks, but they're not online.  The whole set is in the Houghton Library Collection, part of a bequest from Amy Lowell.