Using Return to move between fields, then activating the window on the last one was the RISC OS 2 style guide recommendation.
When the shiny new RO3 style guide arrived it recommended using Tab to move between fields and Return to activate the window wherever the cursor was.
Back on topic - I use ThumbCat to generate HTML galleries for writing to CD. These CDs can then be displayed on any machine, not just RISC OS.
It is a nuisance that you have to create a catalogue first (which I always delete afterwards!), then export it as HTML, but I liked the way it produces a three level web site:
1) Thumbnail gallery, clicking an image opens:
2) Medium sized picture, with EXIF info, etc, if required. I set this to be a suitable size for screen display (e.g. 1024x768). Then clicking on the image again opens:
3) Full size image, which with the resolution cameras now tends to reqiure lots of scrolling around to see!