Yeah they are important, they are the spar stiffeners for the main hs spar. They are important, unless this is an april fools joke or they sent you two extra ones.
Yeah, I'm just starting work on my empennage, and it took a bit of digging through the packaging to find these 2 pcs. They were sneakily hidden under the skins in the larger empennage box. So I thought it'd make a great April Fools joke to imply I'd just run across them after finishing the tail.