Assuming you are referring to John on Patmos, eating the bible/scrolls is metaphorical for
taking in and digesting the word of God in a tangible way.
I know this first hand due to an experience I had a few years ago.
I was in the worship team during a prayer evening, it was electric. We did many things that
evening one including covering each other with veils and praying for each other as a symbolic
gesture of wanting to enter into the presence of God.
When I came to my turn, something amazing happen it was as if my entire understanding
was woken up. I went home that night and I just wanted to read the bible, I could not get
enough of it. Every single word seemed to leap out of the bible with new meaning. Even the
small words like it, a, of etc seemed to have massive meaning. I actually rang a friend and
recited several chapters of the bible over the phone to them! This was like 11pm at night.
It was amazing to me to.
It really did feel as if I was eating the bible in a spiritual way, not just eating but drinking it in.
Verses I had read loads of time, I was reading as if it was the first time I had read them.
That feeling lasted for some months. I could not complete a devotional or bible study as my mind
took me all over the place comparing passages, seeing things for the first time.
I remember thinking that this is what John felt like when the scrolls tasted like honey.
Even now while the feelings are not so intense, I often find myself reading the same passages
and getting new things from them, seeing them with fresh spiritual eyes. Gasping in amazement
at the new things to discover.
Something real happened that night, something tangible, a new awaking for me.