As this was the 1911 census then it is highly unlikely that the householder was illiterate.Illiteracy was not as widespread as is commonly thought. Thanks to the growth in freelance schooling, all privately financed, literacy levels had risen to about 92 per cent by 1870 and Forster's Education Act.
It was also the custom for local clergy to assist in completing the forms in the week before the census, and there was also usually a neighbour who could help.
However if the householder could not fill in the schedule, perhaps because he or she was illiterate, the enumerator was to fill it in for them by asking the relevant questions on the doorstep. How many schedules had to be completed in this manner varied from district to district. In 1871 enumerators were asked to record the number of schedules they filled in themselves. In parts of Manchester 25 per cent had to be completed in this manner; in Colyton in Devon the proportion was 7 per cent; and in Christ Church, Spitalfields, the proportion was 15 per cent. In some Welsh-speaking parishes in Anglesey, however, the majority were filled in by the enumerators.
Just to add from the Enumerators Instructions
If, on enquiry for the Schedule, it is delivered to him not filled up, he must fill it up himself, asking all the necessary questions. He should if possible, see the head of the family for that purpose, and obtain the information from him. In the abscence of the Occupier, any other member of the family possessing the requisite intelligence, may supply the necessary particulars.In other censuses, it's the enumerator!
The 1911 census is the only one where the householders schedules are available. For all the censuses before then the schedules have been destroyed, the enumerator filled in the Enumerator Books from the householder schedule, which is what you see.
Stan