Panev.
The piece you refer to is not a gurney flap. RVDT is correct, those flaps are only mounted on the trailing edge side. And mainly on vertical fins.
It's technically called a spoiler (per Bell documentation). The L models, 407, 222 series, etc. have slats.
Like others noted, you can get their purpose de jour depending which engineer you talk to. But its safe to say, the spoilers and slats are there to change undesirable airflow over the horizontal stab.
W1