Green’s Dictionary of Slang

(UK black) to fill up, to crowd.

1999		(con. 1979–80) A. Wheatle Brixton Rock (2004) 37: Why the hell does my G have to come the same day as the blasted old people ram up the Post Office.
2001		(con. 1981) A. Wheatle East of Acre Lane 228: Nuff black yout’ would ram up Streatham cemetery along wid de dead policeman.