While I've always heard it as "and the brown bowl" I see absolutely no sense in speculating about rambeaus, round bowls and all that other nonsense when the words already make perfect sense. Would somebody like to also speculate as to the meaning of the brown bowl in John Barleycorn (penguin version for example)...

Here's little Sir John in a nut-brown bowl,
And brandy in a glass;
And little Sir John in the nut-brown bowl
Proved the stronger man at last.

Just because you drink beer out of glasses, doesn't mean people always did. Brown is the normal colour of glaze added to the outside of stoneware for most traditional bowls and jugs.

:-)
Ian