The crystal size is the same, but non iodized table salt may contain anticaking agents, while pickling/canning salt is pure salt with no additives. If no other additives other then an anticaking agent has been added, for curing, brining, sausage making etc. the two are interchangeable. Though when dissolved in water, the non iodize salt with an anticaking agent may make the water look cloudy so it would not be a good substitute for canning.
