RealGM pages usually carry a small nav / filter / legend table ahead of the
real data table. This returns all tables that parse and clear min_rows,
janitor::clean_names()-ed, so a caller can pick or combine them.
.realgm_tables(doc, min_rows = 1)A list of cleaned data.frames.
An xml_document from .realgm_doc().
Minimum row count for a table to be kept (drops nav/legend).