When TPX starts it needs information on several tables containing vital parameters.
The most important ones are the SMRT (System Management Resource Table), the ACT (Application Definition Table) and the SAMT (Security Action/Message Table). These three need to be specified in the PARM-field of TPX's EXEC-Step.
All other tables can also specified in that PARMS file but there is a JCL-limitation of 100 bytes so space might not fit.
For that you have Panel 10 "Startup Parameters" of the SMRT. Here you can specify the other tables.
To get an overview on all defined tables you can use command "D TBLS" in TPXOPER session.