I think I know what you mean, in what scenario do you want this to happen? For example, in a standard map with randomised NPC's and other events, the NPC's are still gonna go about their business while you're talking to someone, however, if you're wanting a proper story to unfold in the background, for example, during a cutscene, I think you're going to have to put the text into a picture, and then show the picture during the cutscene. Having given the reader enough time to read the text, then remove the picture and put up another one. Do you get what I mean?
There may be a script out there to make this whole process a lot easier, but if there is, I don't know of it, and me personally, I prefer to do things manually.