What you are looking for, can not be achieved with the PDF Pack. Adobe PDF Pack is a bundle of Adobe Document Cloud services. With it, you can easily create, combine, sign, and send PDF files online. You can also convert PDF files into editable Word or Excel files.
You can not compress a pdf file through this service. To compress the pdf file you need to subscribe for Adobe Acrobat DC as this service would give you access for "Optimize Tool"
PDF Optimizer provides many settings for reducing the size of PDF files- Optimizing PDFs in Adobe Acrobat Pro
Hope this answers your query.