Board Thread:Support Requests - Getting Technical/@comment-3032314-20130316004341/@comment-4674838-20130316020322

If you move your test pages into the Template: or File: namespace (even if they're not actually templates or files), then edits made to them will not appear in Wiki Activity.

[Edit: To clarify, I do not believe there is a mechanism for restricting individual pages from Wiki Activity, it's based on namespaces.]

Another possibility is to create your own test wiki where you can test things without flooding Recent Changes or Wiki Activity on your main wiki. Then once you're done testing, you can move/import your templates to your main wiki.