Venus complying with the invitation while it was yet being given, Silas pegged at him with his wooden leg, to call his particular attention to Mr Boffin standing musing before the fire, in the space between the two settles.
I think this is an important representation of Mr. Venus and his character. Though he does not want Mr. Boffin to find the box that Wegg has hidden he also does not want to disrupt the peace. He complies with every command or suggestion that Wegg gives him, even if he thinks it is not a good idea. I feel that Mr. Venus' character is smarter than this though, this act of compliance seems to be a way to mediate a given situation (almost as a form of manipulation), especially since later on in the chapter Mr. Venus and Wegg get into a fight, thus, showing that he remains docile and dormant until aggression is needed.