Green’s Dictionary of Slang

roger n.³

(UK Und.) a suitcase.

1665		implied in bite the roger
1674		Head Canting Academy (2nd edn).
1688		J. Shirley Triumph of Wit 214: A Cloak-bag Roger [...] Cut the Cloak-bag Flick the Roger.
c.1698		B.E. Dict. Canting Crew n.p.: Roger, c. a Portmantle [sic].
1707		J. Shirley Triumph of Wit (5 edn).
1725		New Canting Dict. n.p.: roger a Portmanteau.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. 1725].
1754		Scoundrel’s Dict. 16: A Cloak-bag – Roger.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
a.1790		H.T. Potter New Dict. Cant (1795).
1809		G. Andrewes Dict. Sl. and Cant.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1835		G. Kent Modern Flash Dict.
1848		Flash Dict. in Sinks of London Laid Open.
1859		Matsell Vocabulum.

In phrases

bite the roger (v.)

to steal a portmanteau.

1665		Head Eng. Rogue I 47: Bite the Peter or Roger, Steal the Portmantle or Cloak-bag.
1674		Head Canting Academy (2nd edn) n.p.: bite the roger Steal the Portmanteau.
1719		A. Smith Lives of Most Notorious Highway-men, etc. (1926) 202: [...] Bite the Roger, i.e., to steal the portmanteau.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.
1754		Scoundrel’s Dict. 19: To steal a Portmanteau – Bite the Roger.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.