It is in principle possible to configure TOPCAT to work with table file formats and schemes other than the ones listed in this section. It does not require any upgrade of TOPCAT itself, but you have to write or otherwise acquire an input/output/scheme handler for the table format in question.
The steps that you need to take are:
uk.ac.starlink.table.TableBuilderfor input handlers,
uk.ac.starlink.table.StarTableWriterfor output handlers,
uk.ac.starlink.table.TableSchemefor scheme handlers.
startable.readersfor input handlers,
startable.writersfor output handlers,
startable.schemesfor scheme handlers.
Explaining how to write such handlers is beyond the scope of this document - see the user document and javadocs for STIL.