Is it ok to store a table saw outdoors in a crate?
Table saw tables are often made of cast iron, which is very susceptible to rust. I keep a plywood cover on mine at all times because a humid day can cause an orange film to form. There are products that help with that, but they need to be applied after each use.
I suggest that you try and cover or seal moisture out of the table, if not the motor and other metal components. Desiccant material can help absorb moisture in the air, but you won't reduce humidity if not in a contained space. Any exchange of outdoor air will render it ineffective.