Hello @Cincinnati.Retrouvaille ,
At this time RSVP blocks are mainly for quick-click reporting for contacts to state if they're attending an event or not, so there isn't a comment section. If you're wanting a way to mark RSVPs and collect comments, I'd suggest using a survey page, with a multiple choice question for whether or not they wish to attend, and a short answer question to leave comments. You can link to the survey page by copying its shareable URL, and pasting it into your email as a text, image, or button link.
See also:
Support Tips
"There's a multitude of ways to engage your audience through us using your social platforms - via ads, social post metrics, email links, and more! " - Will
See ArticleSupport Tips
"Target your most engaged contacts by creating a segment. Create a special offer or show your appreciation!" - Caitlin
See ArticleSupport Tips
"Greet new contacts with one or more automated Welcome Emails depending on their interests or your business goals." - Nick
See Article