All you had to do was Google What is a salt chair? and you could have found this out on your own. I did it for you, and here is a definition I found: Unlike chairs that have widely splayed legs, Salt chairs can be placed next to each other without wasting a lot of space in between.
Salt Chair The compact footprint of the Salt Chair makes it a smart choice for cafes or any location where you want to seat as many people as possible around a table or in a defined space. Unlike chairs that have widely splayed legs, Salt chairs can be placed next to each other without wasting a lot of space in between. This Shaker-style chair is a timeless classic, and its lack of ornament and unnecessary excess makes it befitting of the modern aesthetic. It is finished in a water-based opaque paint that really makes the Chair’s profile pop. The color may appear inconsistent with the name of this item, but this Chair is as fundamental as the salt shaker on your table. The Salt Chair is unpretentious, familiar and made for everyday use.