Welcome to Just Answer and thanks for your question. Table salt contains anti-caking agents that can cause the water/liquid the food is brined in to look less than clear. There are no health concerns with using it. It is just a visual preference. Most cooks use kosher salt because it is much cheaper than sea salt. If you have a cheap source of sea salt, that is fine to use, but kosher salt will give a better-looking finished product than table salt. There would be no noticeable taste difference regardless of which one you use.
LOL. You may find kosher salt in bags, or it may be in the pickling section of your grocery store. It costs about twice what the familiar blue round boxed Morton's table salt does. Real sea salt on the other hand (fleur de sel) can be $30-40 a pound. While it might be nice to use it for your delicate homemade crackers to go with your grandma's famous foie gras, it definitely isn't something you want to use for pickling or putting up green beans
Thank you for the kind words. Good luck with your cooking.