By definition, pH is a measure of the hydrogen ions in an aqueous solution. As table salt, in its pure form, is not dissolved in water, it has no pH.
When one dissolves sodium chloride in water, the ionic compound dissociates into sodium ions and chloride ions. These ions do not interact with the hydrogen or hydroxide ions of water and thus do not affect the pH of the solution in which they dissolve. They do, however, affect other characteristics of the water. When mixed with sodium chloride in too great a concentration, water is no longer fit to drink.