Hey yo, wait a minute, why should I spend my time caring about levels in this game? It's an action-rpg, I shouldn't have to worry about my level!
You are incredibly wrong, my stupid little friend. Levels are almost too important in this game. By gaining a level, two things are accomplished:
You will notice on your life bar has large tomatoes and small tomatoes. Each large tomato is worth 16 HP, and each small one is worth 4 HP. At Level 1 you only have 16 HP, so you have 1 large tomato. For each level gained, you gain 1 large tomato. If you're ever confused, just press Select and view your information to see your HP in numerical form.
Enough already, we came here for the chart!
Of course. This chart will tell you how much experience is required to reach the next level. The total experience is how much total experience needed, and additional experience is how much more experience you need to get to this level (it's total experience - total experience of the previous level).