Calling something finite means it has an end or finishing point. Preparing for a standardized test might be unpleasant, but you have to remember that the work is finite; you won't be doing it forever.
Most people are far more familiar with the word finite when they see it inside the word infinite, or without end. Finite can be used for conceptual things, like time: "Life is finite, so we should live it to the fullest." It can also be used for more tangible things: "We have to be careful with the cooking, we only have a finite amount of fuel." You might want to think of things being finito — a word that looks a lot like finite — to remember that it means, "with an end."