(1) As can be seen from the table 1, the mass and length of the pendulum ball are the same, the swing angle changes, and the swing period remains unchanged;

As can be seen from Table 2, the swinging ball has the same mass and angle, and the longer the swinging length, the longer the swinging period.

As can be seen from Table 3, the swing length and swing angle are the same, the swing ball quality changes, and the swing period remains unchanged;

It can be seen that the swing period of a simple pendulum has nothing to do with the swing angle and the mass of the pendulum ball, but with the swing length. The longer the swing length, the greater the swing period.

(2) The application of simple pendulum isochronism in life is mechanical wall clock;

(3) The mechanical pendulum clock moves too fast. Experiments show that the pendulum length can be adjusted longer.

So the answer is: (1) The swing period of a simple pendulum has nothing to do with the swing angle and the mass of the pendulum ball, but with the swing length. The longer the swing length, the greater the swing period;

(2) the application of mechanical clocks and watches in life;

(3) The mechanical pendulum clock goes too fast, so adjust it longer.