Green’s Dictionary of Slang

nonsense; thus rimble-ramble adj., nonsensical, absurd.

1690		Pagan Prince 20: It was that the greatest part of the Task was only Rimble ramble Discourse.
1696		Motteux (trans.) Gargantua and Pantagruel (1927) II Bk IV 264: I hate a gibble-gabble, and a rimble-ramble talk. I am for a man of brevity.
1796		Delicate Embarrassments 2 61: All this rimble-ramble about your son and my daughter does not signify three farthings’.
1915		M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 205: rimble-ramble, nonsense. ‘I should think college students could carry on a sensible conversation and leave such rimble-ramble alone.’.