Well, he gave me a bunch of little tests, ranging from patterns and design recollection, to maths and language skills. The test I got 99th on was spelling.
The main reason I asked was because I got a little freaked out. The way my mind saw it was on a first to last basis, with 1st being the best, and 100th being the worst. So, when I saw "99th" I thought I'd come in "99th place" out of 100, so to speak, meaning I'd done very badly, but it seems that's not how it works...
It's all still a little confusing to me the way they do it

but thanks for explaining it to me

So what that test score means is that you are probably a very good speller, since on that test you performed better than 99% of people.