When your PST file starts increasing in size, it may cause problems for you in opening it in MS Outlook. In such cases, you need a PST Break application. I suggest you to use the MailsDaddy PST split tool which is always in high demand. This utility works without installing any other applications on the system. It is a standalone utility that breaks any large Outlook PST file into smaller sizes.
For more info: https://www.mailsdaddy.com/pst-split-tool/