Will this relay handle my current and voltage requirements?
This relay is inappropriate for what you want to do.  You need to actually read the datasheet.  In the middle of the first page for #4, RATING, it clearly says 125 VAC.  Therefore 240 V is well out of spec.



What part of this is so confusing?

As for the current rating, if it says it's good for 20 A, then you can run 20 A thru it.  11 A would be fine, if you weren't violating other specs.