This function should be called immediately after a call to odfTable in a code chunk
in an odfWeave document. Legal values for numformat are 'A', 'a', 'I', 'i', and '1'.
If numformat is 'A' or 'a', numlettersync specifies what style of numbering
to use after the first 26 tables. If numlettersync is true, the next 26
tables will be numbered 'AA', 'BB', ..., 'ZZ', 'AAA', 'BBB', etc.
If numlettersync is false, the subsequent tables will be numbered 'AA', 'AB',
..., 'AZ', 'BA', 'BB', ..., 'BZ', etc.
The default formula, which numbers tables consecutively, is usually desired,
but you could specify a formula of 'Table+10' to have your tables
numbered 1, 11, 21, etc.