Is there something treat as block formats in the content you copied?
Like lists, headers and so on. Quill-better-table module can not support these in table cells.
But inline formats, it works well.
I haven't found a good way to support block in table cell yet.
It was also mentioned in #7 and #20 , really a problem.
Thanks for your report, and I will temporarily close this issue, we could discuss this in #20 .