For the confused, pickled eggs are frequently found in pubs and fish & chip shops in the UK.

http://www.british-history.ac.uk/report.aspx?compid=119436#s3

Notes that an Inn in Clerkenwell, London was called The Pickled Egg at some point before 1700:

A few of these inns—Sir John Oldcastle's, the Cock and the Pickled Egg in what is now Crawford Passage—predated the building development under Baynes and Warner.

(From the same page, Warner acquired the land in 1703, and died in 1721. The pub closed in 1874.)

Crawford Passage was known as Pickled Egg Walk, apparently after the name of the inn.

I've heard of that, but never seen it here in western Canada. In fact, the only pickeld eggs I've ever seen were Asian.

Where do you live that this strange practice occurs?

Are there pickled onions as well? It was explained to me that the pickles were complimentary foods so some pubs would stock up on the savoury ones it would increase thirst so people buy more beer. But in fish and chip shops which generally have onions it is sweeter for the contrast of the salty fish/chips.