Its a known issue, uninstall it for now. You can try a newer version later when it comes out.
Visit this link, scroll a bit down and you will see this response from Dell support https://www.dell.com/community/en/conversations/latitude/supportassist-agent-is-taking-10-gb-of-ram/652e70423a8e0b64ea481175
Until the new version of SupportAssist is available, it would be prudent to uninstall the current version.