I use a text editor and some margin: I think the limit is 64000 characters HTML, not 64000 in BBCode. If you count the characters in a text editor, the result may or may not fit if it's close to 64000.
I think that's what lead to this error for tables much smaller than 64000 characters:
I'm trying to post a (big) table on Bitcointalk, to show the results of a giveaway. I know the maximum post size is 64000 bytes. My post is just over half that size, and I get this error:
INVALID BBCODE: loop, probably unclosed tags
The BBcode is valid. If I make it a bit shorter by taking out a few rows, I can post it.
And it looks like there's a bug: recently one of my topics was cut short without getting an error:
This topic was cut short: without giving an error about the 64kB limit, the last part was just cut off.
I would really like to see exceptions from this restriction for some users (me me me !). I sometimes create
a thread in Archival for very long posts, but it would be much easier with a much higher limit. Especially BBCode and tables easily reach 64k characters.