Analysis: What's Up With the Title?
The title isn't super-creative. No cute puns or crazy references here, it's pretty much all business. Still, it does tell us a few important things, though.
First, this is a lyrical poem—a short, almost songlike reflection on a specific, personal experience. That category of poem tells us as readers to pay close attention to the context as we read. In this case, all the metaphors and images can be applied, with a fair amount of certainly, to Keats's experience of reading Chapman's Homer.
Also, it is interesting that Keats isn't "reading" Chapman's Homer—he is "looking into" it. This sets us up for the imagery of new worlds and exploration, but it also tells us how passionate Keats is. He is inspired by a brief encounter with the work—he isn't studying it or analyzing it, he's just looking into it. It sure doesn't take much to get him going.
Remember too that this poem isn't about Homer, and it's not even about his work. It's about the pure beauty of poetry. It's about Chapman's specific poetic powers in his translation, something that that title brings to our attention from the very start.