Hi Milette, it would help to know a bit more about your experience before offering our opinions.
Conceptually, it is likely to make sense to combine very small projects (webinars, in your case) into a project for the sake of reporting and treat each deliverable as a milestone. This might make it easier for your to present your experience and place dates for these projects.
However, it would be far easier to give you a better answer if you provided more information about what exactly you worked on.

Im a little concerned PMI will reject my application as "operations" if they see a bunch of small projects described. Is it better to lump them together? Instead of listing out the 10 webinars as separate projects, can I describe them as one big project with 10 sub-projects? Or will this be rejected for not giving individual projects?

I'd also love to hear from anyone with a similar background managing small projects who was able to get their application approved to ease my anxiety. Thank you!