Yeah, I think you are too far west in Texas for "duke's" mayo. Will have to look in the groc if they make it in pint jars, I only buy qt jars. At $3 to $5 a jar, if I can find it on sale, I figure that it wouldn't kill me if I didn't like it. But I like it and is as good as Hellman's so...
Greybeard is right, the size and density of the bales varies but we figure an average 4 x 5 round bale here in the 800 lb range and the ones we usually make with the big baler are 5 x 5 1/2 to 5 x 6. Average in the 1200 + range. Yes, make sure the flat side is not on the bottom when they load it. I have many times had it loaded on a p u truck so when you drop the tailgate it can be "rolled" off. Never tried to get it on a pallet but usually would figure out where I wanted it, tailgate down, back up fast and hit the brakes....it rolls right off. I usually took the tailgate off so it wouldn't bend it. Or head up a hill quick....let the clutch out with a jerk and off it would come. If you have a tree where you want it, put the pallet in front of the tree, do the back up and hit the brakes quick and it might roll off on the pallet and the tree will stop it from continuing to roll. Done that before without the pallet under it. That's a redneck yankee way of getting it off when you are female and the only one around to get it off the truck with no tractor.
It is easier to "unwind" the hay off it to feed if the flat side is down, round part on the "sides" so that you are taking it off like a spool of thread.