Original: He is a parody of the Q and M characters from the Bond series, and his surname is a play on a common movie convention, 'exposition' - the conveyance of critical elements of plot through dialogue.
Simplified: He is a parody of the Q and M characters from the Bond series, and his surname ('Exposition') is a play on a common movie convention, 'exposition', which is the conveyance of critical elements of plot through dialogue.