Rogue Trader was intended to be played with a GM and the scenarios therein are written out as snippets for him to develop scenarios from, in the tradition of roleplaying game 'plot hooks'. Using the first on the list as an example (grabs copy of Rogue Trader,)
'The governor of a farming world has lost most of his crop/herds to a raiding party from a rival Imperial world. The authorities on Earth are not interested in local squabbles or excuses and will replace the governor unless his quotas are met. A counter raid must be mounted to recover the stolen stock.'
That's as much information as any of the 'player motives' in the segment titled 'Plot Generator' contain, and again quoting from the book:
'The charts below have been designed to help the GM invent plots for games and campaigns. These are only starting points of course - and it is up to the GM to let his imagination take over, filling in gaps and inventing extra detail to complete the story. Two or more plotlines can be merged together, the number of possible combinations is thus very large indeed.
Forces have only been referred to in general terms, as it would be pointless to try and cover every permutation of alien type and force size. The GM must adapt the plot specifically to utilise the models available to the players. The points system can be used as a basis for providing fair sides, although any special plot related objectives or problems should be born in mind.'
There's only actually one actually-developed scenario - the fight between some surviving Crimson Fists and Thrugg Bullneck's Orks on Rynn's World - in the book.