Ah yes. The Julius Smith lecture at the start of Horror on the Orient Express is very much like this. Around two page of text about his experiences with ghost sightings. In the end, one of the PCs started a fire at the Challenger Institute just to shut him up (he set a pot plant alight).The much-loved Call of Cthulhu scenario Heart of Darkness was a bad offender for this. There's about a page and a half of text to read out that my players started to lose concentration with half way through and suddenly started ordering pizza. Always a bad sign in my experience.
I recommend breaking this text up and having it needed to be sought out in true Call of Cthulhu fashion. Just fudge the rolls so the players find all the data, it doesn't matter if they get 'unearned' experience rolls if it makes the game more fun.
The worst of it was that the lecture has nothing to do with the rest of the plot.