Assuming that you're on TD14+ then this is done using a DBQL (query logging) option. Look at the USECOUNT option which is set for specific databases (https://info.teradata.com/HTMLPubs/DB_TTU_15_10/index.html#page/SQL_Reference/B035_1144_151K/BEGIN_Q...).
I'm guessing that this is updated when the query log buffer(s) get flushed from cache to disk. By default that is every 10 minutes (at worst). If a buffer fills earlier then it will get flushed earlier.
And I recommend that you use DBC.TablesV and not DBC.Tables.