It is needed to go through all the trace to collect each SQL statement so, the larger the file size is, the longer the time it take.
Then for each SQL statement collected, Find SQL will retrieve the execution plan.
WORKAROUND
Specifying a collecting criteria to reduce the total number of SQL collected might help.
This way we will retrieve the execution plan only for the desired SQL statement (anyway the trace file still has to go through completely).
To specify the criteria,
1. Click "Show Collect Criteria" hyperlink at the lower left corner in the "Add SQL Trace Search" dialog.
2. Click the plus sign to add a new condition
For example And
Application Name Equals Gestion
STATUSEnhancement request number ST-118914 has been submitted to Development for consideration in a future release of SQL Optimizer for SQL Server