Got a direct answer from Fletcher Penney (thanks!):
- quote -
You use a "+" in the column formatting line:
Sample table | long cell |
------------ | ---------+ |
test | sd lsd ls dksa dkasdkjsa dkasj dk sak jdk asdkja sdk
aslkd jaslkdjsakjdsakd asjdk jasdkjaskdjaskd sakj dk jsakjdks jdkj
sakdj k sajdk jsakd jskajdsdjk
- /quote -
(where there are no line breaks in the long string of gobbledy-gook...