Inserting a new name when you've missed one out also takes a looong time. If it's near the end of a section, adding it at the end and then moving it up is a lot faster. Best to check each screen's-worth as you key and not just leave it all to the end.
If you use my trick of keying all the names in one section and splitting into sections for towns at the end (to take advantage of the multiple acceptance of names like Dvd not in the menu), then do the sectioning working backwards from the end to reduce the number of records moved each time.
WAP need to investigate the reason for the slowth. As a software engineer, I recognise this as a classic case of testing only with a small number of entries and/or on a higher spec machine than most customers have. Rewinding to the first image of a multi-image set for checking also takes an annoying length of time.