If you're satiable, you are capable of feeling full or satisfied. An easily satiable dinner guest might eat one serving of lasagna, pat his stomach, and say, "Ah, that was delicious."
A person who is satiable can be sated or satisfied — for some reason, though, it's much more common to see the word insatiable, which has the opposite meaning. If you're insatiable, you can never be satisfied, no matter how much you have. Both words come from the verb satiate, "satisfy to to full," from the Latin root satis, "enough."