Green’s Dictionary of Slang

tot v.¹

to drink a dram.

1939

H.E. Bates My Uncle Silas 26: Uncle Silas said swiftly ‘Tot out,’ and I uncorked the wine bottle while he found the glasses.

In phrases

tot out (v.)

to pour drinks for a goup.

1879

H. Hartigan Stray Leaves (2nd ser.) 36: [O]ne of the company, having evidently exceeded his allowance, accused Daiby of unfairness in ‘totting out’.