Josh,
I've been going back and forth with evernote support (who have been really awesome and responsive) and I've come to realize that if I use an external mouse I can spell check a word in a table. It is only when I control-click on my MacBook trackpad that it doesn't work. It seems that control-clicking with the trackpad highlights the whole table instead of acting on the word itself.
I never use an external mouse with my MacBook. It would inconvenient to impossible for me to do so most of the time.
Give it a try if you can. It could be an ok workaround.
I will continue to ask evernote to fix this problem.
Good luck,
-Eric