You can't embed PDF files into a PowerPoint 2016 for Mac presentation. However, you can insert a link to the PDF file into your presentation so that you can open and view it during your slide show.
Insert a link to a PDF file
Save the PDF you want to use to the same location as your presentation.
On the slide where you'd like to put a link to the PDF, select the text, shape, or photo you'd like to be hyperlinked to the PDF file.
Go to Insert > Hyperlink and choose Web Page or File.
Click Select and browse to the location where your PDF file is saved. When you're finished, click OK.
Note: Make sure that your presentation and the PDF file are saved to the same location when you present, or your link will be broken.