All-in-one File Importer for Confluence allows users to import any document format to Confluence as pages. Some of the are supported document formats are:
If you haven't installed, please install from Atlassian Marketplace here: https://marketplace.atlassian.com/apps/1221333
Once installed, you can use this add-on from page action icon (...) on the right.
Click on Convert documents to Confluence pages to open add-on window.
This will open window where you can upload documents and import them as Confluence page.
Finally, you will see link to imported page.