Green’s Dictionary of Slang

roger n.3

[? dial. roger, the paunch of a pig]

(UK Und.) a suitcase.

implied in bite the roger
[UK]Head Canting Academy (2nd edn).
[UK]B.E. Dict. Canting Crew n.p.: Roger, c. a Portmantle [sic].
[UK]J. Shirley Triumph of Wit.
[UK]New Canting Dict. n.p.: roger a Portmanteau.
[UK]Bailey Universal Etym. Eng. Dict. [as cit. 1725].
[UK]Scoundrel’s Dict. 16: A Cloak-bag – Roger.
[UK]Grose Classical Dict. of the Vulgar Tongue.
[UK]H.T. Potter New Dict. Cant (1795).
[UK]G. Andrewes Dict. Sl. and Cant.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]G. Kent Modern Flash Dict.
[UK]Flash Dict. in Sinks of London Laid Open.
[US]Matsell Vocabulum.

In phrases

bite the roger (v.)

to steal a portmanteau.

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