All tables have a database prefix, e.g. tickets could be traq_tickets.
This makes it possible to run Traq in a database with other tables, or even multiple Traq installs on a single database. The need for this is very niche and makes maintaining things on the backend somewhat complex, especially for large queries that join multiple tables together.
Considering most hosting providers these days allow for multiple databases, the need for a table prefix on every table isn't needed anymore.
Table prefix option has been removed during installation and the AdminCP has a warning message stating prefixes will be dropped in 3.11.
Moving ticket to 3.11 to implement the table renaming.
Traq 3.9 will no longer prompt for a table prefix during installation and will have a warning message in the AdminCP stating that a future release (3.11 or 3.12) will rename database tables to remove the prefix.