If a header line is available above the label line, the engine can use it to detect the table start position alternatively or in addition to the label line.
Footer lines are located below a table. An example of a footer line is a row that contains the sum of all column cell entries. If a footer line is available, the engine can use it to detect the end of a table instead of or in addition to further criteria.
If your tables contain empty rows, you need a footer. Otherwise, there
is no way to determine the table bottom.