The capacitance of a capacitor is proportional to the surface area of its plates. So, when the plate area of a capacitor increases, the capacitance also increases.
Capacitance is the ability of a capacitor to store electrical charge. It's measured in Farads (F). A larger surface area of the plates means that the capacitor can store more electrical charge, resulting in an increase in its capacitance.
In simple terms, the bigger the plates, the more charge a capacitor can store, resulting in a higher capacitance.