A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
OLE on the Mac only supports interaction among MS Office components like Word, PowerPoint, Excel, etc. Unlike Windows, no other programs are supported.
In addition, you're using a Windows-style path that you'll have to change to Mac.
However, you can still insert the PDF as a picture:
Sub InsertPhoto()
ActiveWindow.Presentation.Slides(1).Shapes.AddPicture (FileName:="RAID0:Users:YourUserName:Documents:Test.pdf", LinkToFile:=False, SaveWithDocument:=msoTrue, Left:=1, Top:=1, Width:=85, Height:=110).Select
End Sub