I’ve just made a cheddar that called for 1tbs of salt per gallon of milk but there was no mention of salting the cheese whilst drying, is this a different way of salting cheese or should you always salt the cheese whilst drying

Some cheeses, like Gouda, are salted after the press in a brine solution.  Cheddars have the salt added to the curd prior to pressing.  The salt will slow the growth of the culture bacteria, so that the cheese will age properly.  It will also act as a natural preservative and a flavor enhancer.  Salting during drying is not required.  Some people like to do a dry salt rub just prior to waxing to eliminate any contaminants that may have come in contact with the surface during drying.  Good luck with your cheese making and welcome to the forum.  Let us know how you progress.

If u are using Brine then it does not need salting, If its Air dried then I would salt it because its easy to pick up bacteria. Giving a good rub down gives u some insurance that nasty little beasties dont get to the cheese, especially if by chance your wax cracks and has air leaks, or a bubble happens in the wax coating and gets popped later giving u a pinhole air leak.
1 tbsp/gall milk? I would be careful go with your taste, it might be too much, also depending the type of salt, they are not all the same strength.

The 1 tbsp per gallon is what I use for mine; and it works out just right.  The cheese does not taste salty.  For cheddar that is; others may require less.