Is sit not that there is salt added to many food products that we never really think about as being 'processed' and most of which we do not associate with a 'salty' taste. For example, bread, cheese, every kind of smoked fish, bacon, ham, bottled sauces, salad dressings, egg mayonnaise, pickles, butter (unless you deliberately select unsalted) etc.
We never purchase 'ready made' meals. Yesterday at various times I had a kipper, reasonable portion of brie, a couple of pickled dill cucumbers, 2 slices of wholemeal bread and two slices of boiled ham. The only thing I consumed which I know had no added salt was a large portion of Ratatouille that I made with fresh vegetables, olive oil and unsalted butter.
Even in a days reasonably healthy eating we probably absorb more hidden salt than we realise.