Seems to be a point of “Keep with next paragraph” (table properties, Text Flow). If I deselect this option the table behaves regularly. I agree that this could be a bug.
As this setting is, among all, for whole table I consider it as applying to table. For my writing it is always table caption paragraph which follows table - have good reason to keep it ON (as reported in OP). Otherwise tables in document can happen where table is on one page but its caption on subsequent one.
And this is perfectly legitimate. Keep with next paragraph is intended to link table with caption which is a part of main text flow. Now, further experiments have to done to see how the caption “geometry” interacts with table layout (and split which could seriously complicate matters).
My observations so far are Writer’s default configuration is to place caption above the object/table. If to use Writer built-in functionality a manual operation during caption insertion is needed in order to achieve the order, top to bottom: table, then caption.
If to follow @ajlittoz recommendation made once in other context (however not so long back yet which is used in my writing) the document author takes full control of caption creation. In such a case it appears hard to talk about what is Keep with next paragraph, or isn’t, intended for.
Keep with next paragraph is precisely what allows you to control the relationship between caption and table. The alternative way is to jail table and caption in a frame but this won’t work if you spread a table across pages.
I suspect that direct formatting the last row or two of the table to “Keep with next paragraph” might have to be the workaround.
@EarnestAl What would it mean for those writers who seek to work style-based fashion? Opinions are namely to be met on ask.libreoffice that if one follows style-based writing - absolutely no DF. What would it mean for those writers who additionally want use master and sub-documents?
The only other way I can see to ensure that the caption is not stranded from the table is to cut the caption and place it in the last row of the table. That comes with more problems.
The easiest is to hope that the caption line below the table stays with at least one line of the table. Better than evens chance of that happening
Interestingly, one other table in same document, however with all rows being single-paragraph (no line breaks in cells) results in the table not breaking across two pages. That case is at the same time curious as only table last row gets transported to next page. Furthermore, text acting as content of both pages fills page text area properly, as document author expectation are.