Elz,
This is not a "surname change". This is a typical but minor error by folk, or officials of the day or modern transcribers.
If you pay the 1911 census fee, you will be able to see the census form that someone in the household filled in for the census enumerator. In all previous censuses we were unable to access the sheet filled in by our ancestors.
Also the sheet will reveal Eliza's marital status. I could easily have missed him, when I was using the "free" facilty in the 1911 web site!
On the 1881 census there was over 30 different spellings of my mother's Gallagher family.. My mother from the time I was a child used to say "we are " ..gh.." , not to be confused with that "..cher.." lot.
So I spent many months researching GALLAGHER, ignoring, rejecting info on other versions. Can you imagine how foolish I felt when I discovered that her folk were Galliker, Gallagar, Gallaghar etc, before they eventually settled on the GALLAGHER version.
Michael Dixon