This should be faster. I've used something similar before to load the entire English dictionary.
Global text data=""
Global text word=""
Global text c=""
On ajax complete
-> set data to Ajax.lastData
--- repeat len(data) times
--- -> set c to mid(data, loopindex, 1)
--- --- system: c=";"
--- --- -> array: push back word
--- --- -> set word to ""
--- --- else
--- --- -> add c to word