I found that there is 2 typical multi-ball training pattern that Chinese coaches often use for their players.
Multiball 1: 4th ball counter attack
Number 1 pattern is 4th ball counter-attack training. In the modern game, that the opponent will attack right after the serve. This attack is the classical 3rd ball attack. Top Chinese players practice doing the counter-attack to gain an advantage in the next rally. This is called the 4th ball counter-attack multi-ball training.
Some players don’t know what is the 4th ball. So here you are, one, two, three, and four. In the modern game, you need to counter-attack. Never defend the attack of the opponent, but counter-attack it. This is one of the reasons that Chinese players maintain their top ranking.
Here is another example of counter-attack training.
Multiball 2: Forehand drills around the table
The number 2 pattern is the classic forehand topspin everywhere on the table. This is the best exercise to improve the footwork and the power of the forehand topspin. To have a powerful forehand attack, you need to profit the weight transfer by applying the concept “power from the ground”.
Well, this is the classical training drill used a very long time ago. This drill is very important for the footwork because you need to move around the table. You will use your forehand to attack the long ball. And you will learn to do the weight transfer to increase the power of your forehand topspin.