Green’s Dictionary of Slang

an unskilled job, an odd job, e.g. holding horses, carrying parcels; also as v.

1857		T. Wright Dict. Obsolete and Provincial Eng. II 571/2: Hob-job, s. a clumsy job.
1873		B. Waugh Gaol Cradle 123: ‘Hob-jobbing’, to use the vividly descriptive phrase of his class in life, through thirteen months the lad somehow managed to appease [...] the cravings of nature. [Ibid.] 133: Every day not less than seventy thousand boys and girls are actually ‘hob-jobbing about’, utterly helpless, until they hob-job into gaols, penitentiaries, reformatories .