You can easily convert OLM file data into an Outlook PST format with the simple and excellent IMAP mail account method. In this IMAP mail account method users has to first setup an IMAP account, Add IMAP mail account to Outlook for Mac, create Gmail label, and at last move emails from Mac Outlook to IMAP mailbox.
Here I shared a link: https://goo.gl/L9vX8e from where you will learn the complete information about this OLM to PST Conversion method.