They named the whole stinkin' film after the list, so you know it's important.
Like all great symbols, it's devilishly simple: just a list (drawn up by Stern) of the factory workers Schindler wants removed from the concentration camp and taken to his factory. In the factory, they'll be relatively safe until the war's over.
The list echoes another motif in the film. The movie opens with the Germans recording the names of all the arriving Jews and cataloging them for eventual extermination. (The Nazis were known for their obsession with records and lists.) Schindler's list does the exact opposite, making it a most potent symbol of Jewish survival.
Stern knows what this list represents. "This list is an absolute good," he tells Schindler when they're done writing it up at last. "The list is life. All around its margins lies the gulf."
There actually was a list, and it was probably just as ordinary as this one. But the names on that paper represent Jewish survival. It's the ultimate revenge against the Nazis, the final means of thwarting their "Final Solution."