Green’s Dictionary of Slang

1. an undertaker [SE raven, a carrion-eating bird].

1822		Life and Trial of James Mackcoull 11: ‘Odd’s bodikins!’ cried Drake, ‘Here’s the old raven I told you of’.
1865		Newry Examiner 29 July 4/1: Mr Raven was only an undertaker [...] His spouse, Mrs Raven, [...] dressed in a black velvet cloak.

2. a small portion of bread and cheese. [the Biblical story of ravens taking small portions of food to the prophet Elisha].

1909

J. Ware Passing Eng. of the Victorian Era.