UPDATE:
Prevent break tables using addTable
Prevent break tables using HTML
Hello,
The cantSplit option set 'Allow row to break across pages' as false, so if the row content doesn't fit in a page, the whole row moves to the next page.
If you need to keep rows on the same page, then you need to use keepNext and keepLines options available in paragraph contents and paragraph styles.
You can read more about this MS Word behavior on the following pages:
https://word.tips.net/T000865_Keeping_Table_Rows_Together.html
https://word.tips.net/T000864_Keeping_Tables_on_One_Page.html
These samples illustrate how to do it using MS Word, but can set the same options using phpdocx.
Regards.