I apparently got the same kit you did. Those are adhesives for securing the force touch sensor and/or the display to the case.
I found that you can't use both of them; the final result ends up too thick and the screen sticks up. My final solution was to use one of them - the non-Tesa one - in conjunction with the adhesive already present on the force touch sensor to seal it down. Seemed to work for a couple of years until I had to open it up again for a battery replacement.