Green’s Dictionary of Slang

slice (of bread and honey) n.

(Aus.) money.

1948		Smith’s Wkly (Sydney) 25 Dec. 6/3: He never chased very hard after the elusive slice. Which [...] is a short way of saying Slice-of-bread-and-honey, which is a short way of saying money.
1992		P. Corris Matrimonial Causes [ebook] The finance business must be doing all right. Mrs Meadowbank was looking at a nice slice.