The chart is not confusing, okay, I guess it is, because at least one here IS confused.

The chart says:
Ampere Rating | Wire Size Range

10 amp rating | (1) #14-8 (Jerry's note: That means (1), yes *1*, wire sized #14-#8.)

15 amp rating | (2) #14-10 (Jerry's note: That means (2), yes *2*, wires sized #14-#10. Note that the terminal on the 10 amp breaker is rated for a larger wire than on the 15 amp breaker, that's because IT IS NOT rated for (2) wires, just one wire.)

20 amp rating | (1) #14-6 (Jerry's note: That means (1), yes *1*, wire sized #14-#6. Note that the terminal on the 20 amp breaker is again rated for a larger wire than on the 15 amp breaker, that's because IT IS NOT rated for (2) wires, just one wire.)

25 amp rating | same as the 20 amp rated breaker
30 amp rating | same as the 20 amp rated breaker

35 amp rating | #14-2 (Jerry's note: That means (1), yes *1*, wire sized #14-#2.

Now, go down to the sub notes and you will see that sub note 1 means it applies to 1 and 2 pole breakers.

You will see that sub note 2 means that breaker (the one and only one rated for two wires) can use solid and stranded TOGETHER.

So, the 15 amp breaker *is the only breaker on that chart rated to TWO (2) wires, and, that applies to single pole and double pole breakers, and, that you can mix stranded and solid wires together.

BUT ONLY on the 15 amp breaker.

NONE of the other sizes.