Recipe calls for 1/2 tsp kosher salt, how much Table salt is this?

I'd go 1/2 tsp. For anything less than a tablespoon it's not going to make a noticeable difference.

I'd say about 1/3 tsp of table salt which is more dense than kosher salt, plus a lot of table salt has additives to enhance absorption.

In any case, this is really up to you to decide saltiness. Adding more salt is easy; you can't remove salt. I don't use table salt myself, but if someone pointed a gun at my head, I'd probably start with 1/4 tsp and taste along the way.

But that's just me...

What are you making? BB