What is Kosher and how did James perceive this tradition as a kid?

As a child, Ruth was forced to conform with Jewish culture,

They had different tablesettings for every meal; you couldn't mix your meals (dairy meals and meat meals were different); no pork.... no pork chops, no bacon and eggs; you ate what you were supposede to and when you were suppposed to...." That was kosher.....

After Ruth leaves, and she is disowned by much of her family, Ruth drops her Jewish culture altogether.