concatenate two cells by browsing a column

Hello everyone,

I have a small question about the possibility of writing a formula.
I have a table with two columns. One with emails and the other with names of different events where people have registered.
Sometimes there are two identical emails (same person who registered for two events), so I would like to put this second event in the cell next to the first event on the same email address line.
Is this possible?

Thank you