column(1)
is your friend.
$ column -t <<< '"option-y" yank-pop
> "option-z" execute-last-named-cmd
> "option-|" vi-goto-column
> "option-~" _bash_complete-word
> "option-control-?" backward-kill-word
> "control-_" undo
> "control-?" backward-delete-char
> '
"option-y" yank-pop
"option-z" execute-last-named-cmd
"option-|" vi-goto-column
"option-~" _bash_complete-word
"option-control-?" backward-kill-word
"control-_" undo
"control-?" backward-delete-char