The DataView addon can be installed directly from the Atlassian Marketplace.
It converts Excel xlsx files into index files that can then be searched very quickly. These index files need to be stored in a custom directory under the shared-home directory with Confluence Home.
Please ensure there is adequate file system storage space available. Small Excel files are typically less than 1Mb of disk space, but large Excel files with 100,000 cells or more can require as much as 30Mb or more.