Can I efficiently make a pdf out of 10 jpeg images?
You may want to watch this YouTube video - it shows the scenario that I believe you're looking to solve - it uses Preview to create a multi-page PDF.

The steps are:


Open your images in Preview
Select Print from the File menu (or ⌘P)
Click on the "PDF" button in the Print dialog and select "Save as PDF..." from the dropdown
Provide a file name and Save