Yes, you can use multiple rel values on a and even area elements.
The HTML spec says the following:
The rel attribute on a and area elements controls what kinds of links the elements create. The attribute’s value must be a unordered set of unique space-separated tokens.
Source: https://html.spec.whatwg.org/multipage/links.html#attr-hyperlink-rel
Why would you want to do this?
A classic use case is for external links. For example, if you have a link to a social media website in the footer of your website you probably want to add noreferrer and nofollow. The reason for this is because
noreferrer strips referrer information being leaked out and nofollow will stop search engines crawling this link to prevent crawler fatigue.
<a href="https://www.facebook.com/" rel="noreferrer nofollow">Super Facebook Page</a>