Some really interesting selections here, and a great, representative variety of documentary papyri. Includes the Greek and a translation that was not super-colloquial even for 1910, for a work that wants to popularize papyrological discoveries.
Some personal favorites:
Dear Son, come back and start doing some work on the farm instead of whatever you're off doing that's fun, you're killing your mother here;
To whom it may concern, this dude totally sacrificed to the emperor and is definitely NOT a Christian, nope;
Dear Mom, It's not that I'm asking for money or anything, but I'm totally ashamed of how I'm wandering around naked because I spent all my money;
This is a totally legit excerpt from the Sacred Book of Isis and the real, true way to get a Completely Accurate Oracle [tm];
Dear Dad, I made it to Italy to be with the army, oh, and I have a new Roman name now;
Dear Local Magistrate, This woman I know broke into my house and stole my stuff, but I have absolutely NO idea why, because we certainly had never had a problem before this, oh, yeah, and her husband also broke in and stole some of my stuff, please punish them;
Dear Dad, You went to Alexandria without me, and I haaaaaaaate you, and I'm never going to talk to you again, you're so mea, what a meanieboots you are, Love your son;
and my new favorite...
Dear Worshipful Society of Wandering Athletes, thanks for the crown to celebrate my victory over the Britons, and congrats on the new member, Love, Emperor Claudius.