I think it actually reads (or at least was meant to be read) like this:
th-h-ih-s ih-s t-h-eh h-ah-n-d w-r-ih-t-t-eh-n
"This is the hand written"
Or basically:
"This is hand-written"
This is a horrible, horrible example of D'ninglish, on so many levels...

The text on that image was probably used as a place-holder for the concept art, & then they put it in the Prima Guide without realizing what the text said (presumably they didn't send it to RAWA for proof-reading

).
Incidentally, I believe the actual text on the Arch of Kerath in Uru itself is the same text on the Harbor near the Ferry Terminal, & in the 'Hoods (over the doors to the Classroom & the Egg/Seed Room):
"rebahntahno tenee-en shemtee"
"The [something] [verb?]s you (plural)"
A few thoughts:
1- "-tahn" turns a verb into a noun, but "bahn" is unknown, & that would make "o" some kind of new suffix...
2- "ahno" means water, but "bahnt" is unknown.
3- "ten" means "simple" & "nee" means new. Or "tenee" could be completely unrelated.
Being in several prominent places in D'ni, I'm assuming this phrase was a major D'ni motto of some kind, akin to "United We Stand", "E. Pluribus Unum", or "In God We Trust" in the United States. I wish we knew what it meant.
There's a thread about this around here somewhere...