Symbolism, Imagery, Allegory
Ah, the name game. People loved playing the name game back in the Bronze Age—every name stood for something special.
For Jacob's family in particular, names mean a whole lot. Just for an example, let's take a look at Zebulun, whose name isn't created because Z is the last letter in the alphabet. "Whom she bore easily and named Zebulun, by which Leah meant 'exalt,' because with his birth, Leah exalted in her body's ability to heal and to give life once more" (1.2.124).
And from that moment on, Zebulun will always remind Leah of how she exalted in her body's ability to heal. So names can mean a lot of different things: they can celebrate something about the baby, or they can celebrate something about the mother, or they can mean whatever anyone wants, really—as long as they mean something. In this case, Leah names her son after something that pertains to herself.
Names are how we identify ourselves and each other, so what happens if you decide you don't want an identity anymore? Well, Jacob, for one, isn't too thrilled about being Jacob anymore after his sons massacre the people of Shechem: "Jacob cowered and took a new name, Isra'El, so that the people would not remember him as the butcher of Shechem. He fled from the name Jacob, which became another word for 'liar'" (2.8.19).
In this case, Jacob changes his name to avoid the truth. But as we all know, you can't hide from the truth.
Whether it stands for something symbolic or whether it's just a way to hide your identity, you can always count on someone's name to be of importance. Just ask Zafenat Paneh-ah. He'll tell you all about names.