The failing test code illustrates the issue.
The figure illustrates the desired PDF output (obtained by means of the workaround). It ts a sample lab test report.
The first row in the test's table is equivalent to the row containing the section heading in bold on the left (Immunology/Serology), and to the right a few details about the test (execution time, etc.). Those details to the right span 3 columns.
The second row in the test's table is equivalent to the one containig the actual test result (i.e. FSH), notice the last column (Reference Range) is actually a 4-column sub-table, to allow for proper alignment of the ranges.
The results cannot be placed in separate tables, as there are usually many test results per section that outgrow to other pages, thus the first row is used as a header/repeater.