Why didn't the Axis occupied Malta immediatly after the Italian entrance to war?

I know for sure Italy had a planned operation for invading Malta (Operation C3). So why didn’t they invaded the island from day one, right after the Italian declaration of war?
I read and heard a lot of controversy about it. According to German admiral Friedrik Ruge (interviewed after the war) the island was weakly defended in June 1940 only by two or three infantry battalions and four fighter planes.
Italian admiral Angelo Jachino (also in a post-war interview) stated that a succesfull invasion of the Island was unlikely because the Italian fleet, with the exception of the battleships Cavour and Cesare, was not yet ready to engage in open battle both the British and French fleets.
According to historian Erminio Bagnasco an amphibious invasion was extremly hard due to the shores of the island made up of high cliffs rather than plain beaches such as Normandy and that would require special landing crafts that at time simply didn’t exist.