Lee Chong owns a grocery store on the Row and he employs tons of family members there. Since everyone in town owes him money, he's kind of like the local banker. There are things about him that not even the narrator knows, like what he does with his money, or if he even has any at all (1.3). So, what can we figure out about him?
Okay, so the Asian Store Owner might be a little cliché, but it does have some basis in truth: a lot of Chinese immigrants did own grocery stores in California, and only merchants could bring their families over. So it makes sense that (1) Lee Chong owns a grocery store, and (2) his family works there.
Other than that, it's hard to say why Lee Chong is a bit of a mystery. It may have something to do with the fact that he's Chinese, and therefore stereotypically mysterious. (Steinbeck didn't get the political correctness memo.) A lot of what Lee Chong does is described as "Oriental" or "Chinese," like his decision to forgive Mack the boys their frog debt "all in an Oriental moment" or his reaction to Horace Abbeville's death, "a calm and eternal Chinese sorrow" (1.16).
According to the narrator, Lee Chong is caught between two different universes. He's "an Asiatic planet held to its orbit by the pull of Lao Tze and held away from Lao Tze by the centrifugality of abacus and cash register" (2.1). In other words, he's caught between the spirituality of Chinese philosophical tradition—and the cold, hard capitalism of America.
Here's a little more detail: Lao Tze is one of the founding philosophers of Taoism. It would take at least a whole other Shmoop module to explain all about Taoism, but for now let's say it's a religion/way of life that emphasizes generosity and moral behavior and discourages selfishness. So on the one hand, Lee Chong wants to follow the teachings of Lao Tze; and on the other hand, he'd also like to make a living.
The result is that Lee Chong extends huge amounts of credit and "trusts his customers until further trust became ridiculous" (1.3). But he's also not above taking advantage of his customers once in a while. For example, when Mack and the boys are paying Lee Chong in frogs, Lee Chong raises his prices because he knows that none of the other stores in town are about to start accepting frogs as currency.
These two influences—Lao Tze and the cash register—make Lee Chong a complicated character and also make it hard to know how he'll behave in a given situation. For instance, did you expect him to forgive Mack and the boys' frog debt? We didn't.