How to excludes more then one library from Search results in SharePoint 2013 on-premise?
Create crawl rules to exclude specific paths (libraries) when crawling content.
- Open Central Administration -> Application Management -> Manage Service Applications -> Search Service Application.
- On the Search Administration page, click Crawl Rules.
- Click New Crawl Rule. In the Crawl Configuration, select Exclude.
Useful link: Manage crawl rules in SharePoint Server 2013
You can prevent a library from being searched in the Site's Administration: