What does the expression Hey ho said roly mean?

Probably drawn from the nursery rhyme "A Frog He Would a-Wooing Go" (c.1883?). No specific meaning as such, but typically used as longer version of the verbal shrug 'hey, ho', a slightly archaic term seemingly coming back in to vogue - Collin's English Dictionary is reintroducing the phrase (Sept 2009) due to it's increasing popularity, partly attributed to the internet and social networking sites.

See

'http://www.landofnurseryrhymes.co.uk/htm_pages/A%20Frog%20He%20Would%20A-Wooing%20Go.htm'

for Words of the rhyme. There also appear to be rather grubbier versions available, but I leave that to you and the Well Known Search Engines!