Too much of anything is not good for you!

Table salt is largely rock salt that has been crushed and purified. There is little real chemical difference as both are largely sodium chloride.
Table salt will occasionally have trace quantities of other things added such as iodine to prevent people getting goitres.

As you might expect, the guide to many things saline is found in the Wikipedia’s entry on “sodium chloride”, a term fairly interchangeable with table salt. A separate Wiki article on rock salt is found under “halite”. Sea salt, is seems, is generally regarded worldwide as superior to its landbound relative.