Vegetable "jam" with salt instead of sugar
No! A cup of salt is an enormous amount and would be dangerous for anyone who ate it, although they are unlikely to be able to swallow it in the first place as it would taste awful.

Preserving vegetables can be done with or without preservative agents like sugar, salt, and acid but  you won't be able to use your bread machine's jam making function. I would highly doubt that the jam made in your bread maker would be good for a year anyway, as long-term preservation requires canning and processing which isn't going to be done by a bread machine.