stat/file is a SAP Parameter attribute which is used to control Name of the statistic file information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Examples of general information of statistic file
Date start of transaction, end of transaction, T-code, report, dynpro.
Database statistics: Inserts, updates, selects, fetches, deletes table
related statistics.
Roll statistics: Roll-in, roll-out, maximum roll area
Semaphore statistics: Lock time
For each screen change a statistical record is written to a file that is
specified in parameter stat/file. The work processes first create a
local buffer for the data. When this is full, the buffer content is
emptied to the statistical file.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.