Importing a policy, as described in KB 53918, and leaving a large number of template files behind can cause UI performance issues.
Template files are added to the <DLP_INSTALL>/Protect/config/templates directory. Once the template is imported, the file is no longer needed in the templates directory. They can be deleted. Keeping too many files in that directory can cause UI performance issues.
It is recommended to delete the templates after they are imported.