"Send PDF to Outline" is a part of OS X PDF Services that brings functions of a virtual printer. It allows you to import documents, files or web pages as PDF attachments or printouts from Safari, Finder or any app with printing support to Outline.
To activate this feature, you will need to download and install "Print to Outline" utility on your Mac by this link. After that just run downloaded file and follow instructions of Installer until the process is over.
Go back to data you would like to save to Outline and call Print dialog window (press ⌘+P or go to File -> Print). Outline will appear in a PDF dropdown menu and you can use it every time when you want to quickly save required information. Your data will be saved into Outline directly as attached PDF file and its printout in Inbox section of the Unfiled notebook.
Use opportunities of Print dialog window to indicate how many pages you want to save. To do this just click on dropdown menu for pages and choose required pages and their amount.