Is it similar to gaffer tape? No idea about the show but I can say two things about that for handguns... Aesthetics, and comfort. Some handles can feel uncomfortable, too thin, or rough especially with larger caliber or more kickback.
Tape can be used to provide a textured grip to any ordinary point-of-contact with a weapon. No tape I've ever seen will conceal fingerprints, and in the 21st century it would be forensic suicide to touch adhesive paraphernalia your bare hands.
