Eames comes from the old word EME, meaning "uncle". Maybe it was a nickname, or it identified someone whose only claim to fame was that he was the uncle of a better known person. Cabell may have been a given name, according to Reaney (Dictionary of British Surnames). He gives an example, Kabell son of William living in 1286; nothing on the meaning. He also suggests a metonymic for a ropemaker, cable = rope, or something to do with CABAL, an old word for a horse. Take your pick.