Will you hob or nob with me? a question formerly in fashion at polite tables, signifying a request or challenge to drink a glass of wine with the proposer: if the party challenged answered Nob, they were to chuse whether white or red. This foolish custom is said to have originated in the days of good queen Bess, thus: when great chimnies were in fashion, there was at each corner of the hearth, or grate, a small elevated projection, called the hob; and behind it a seat. In winter time the beer was placed on the hob to warm: and the cold beer was set on a small table, said to have been called the nob; so that the question, Will you have hob or nob? seems only to have meant, Will you have warm or cold beer? i.e. beer from the hob, or beer from the nob.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Hob * HobberdehoyNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes