The revelation from Jesus Christ, which God gave him to show his servants what must soon take place.
Revelation 1:1 (portion)
As has been pointed out by numerous commentaries, the language of the opening of Revelation seems to be a short time-frame. Additionally, the end of Revelation indicates that John was not to seal up the book, in contrast to the instructions given to Daniel at the end of his, since the time was at hand. Unless you stretch the language severely, soon would tend to indicate the immediacy of the events in question.
In this book, however, you will notice a transition in Revelation 10.
Then I was told, “You must prophesy again about many peoples, nations, languages and kings.”
Revelation 10:11
Quite clearly, this begins a new prophetic segment, as indicated by the one speaking. This means it does not necessarily need to fall under the same time period as originally indicated of “what must soon take place”.
Indeed, it appears that up to this point, the book focuses on near events, and, as the speaker indicated, he then goes to prophesy again, that is, apparently, a different prophecy, “about many peoples, nations, languages and kings”.
This also indicates a subject of prophecy change. As the first book appears to point to Jerusalem in its tribulations in 70AD, the things transpiring “soon”, now the focus shifts to the “many”, and no longer the original subject.
As such, there is a small digression, recovering a few events that had already transpired, and much of the rest of the book focuses on something else.
It is also worth noting that the “soon” should not apply to the entire book, nor the closing that they must “soon take place”, since the events after the milliennium, if viewed literally, must of obvious necessity, take place at least some one thousand years later.
Therefore, the closing words of the book soon taking place do not negate the rest of the time elements, but concern primarily the then soon to be taking place events, presumably Jerusalem, while the rest of the prophecy, or the second prophecy, stretch out through some time that follows.