If Chinese eat with chop sticks...how would they cut their meat at the table?!

Well, we usually cut the meat before eating. Traditionally, the Chinese didn't really eat western meals like steak which require you cut the meat at the dining table. When my mom makes chicken, she chops it up right before we eat it. It might sound weird to you but it's pretty common in Chinese house holds.

By the way, sweet and sour chicken is more of a western dish.

To be honest, we don't really have the greatest table manners. We basically shovel rice into our mouths from the rice bowl with our chopsticks. And we slurp when we eat noodles. But it's all good. (:

Normally Chinese food is in small enough pieces that it can be picked up by the chopsticks. If the piece to too big for one bite then the person will just bite off a piece and eat it in two bites. You'll never see things like a huge piece of steak that needs a fork & knife. Normally the dishes have pieces that can be eaten in one or two bites. Chicken is usually sliced up. Beef is also normally sliced and served with vegetables that can be eaten in two bites or less. You just hold the larger pieces in your chopstick and take two bites. It's fine that way.

Chinese (and other chopsticks-using cultures) cut up their meat etc. into bite-size pieces as much as possible. Sometimes a person has to "cut" their food (separate it) using chopsticks -- this is done by using the chopsticks to spread the food until it breaks apart. An adult can usually do this with one hand, but a child might use the chopsticks with two hands (one in each hand).

So, in answer to your question, no, a knife would not be proper table manners for them.

Experience

Generally the meat is cut up before it's cooked, so it's either served boneless or have small amounts of bone which you can remove easily by nibbling.

Meat that is served similar to western styles (e.g. 1/4 chicken) are usually from South-East Asian cuisines, and they usually use a spoon and fork.

The meat is already cut into bite size morsels.
I believe it is polite for the cooks to do most of the work for cutting the food. Their thinking is "Why do half of the job and make the guest cut up their own meat."

For items that are still a bit too large, it is acceptable to take a bite and put it back on your plate.

It's considered bad manners to "stab" food with a chopstick.