There are a number of ways to interact with other users in a room.
1. You can talk to anyone who is on your table with anyone else on that table being able to interact with that conversation, you also have the ability to move tables if you wish to speak to others outside of your table.
2. If you wish to have a private conversation with someone on your table you can use the “Whisper” button, this then allows you to speak directly and privately to another user, this is indicated with a line that shows you are linked for a conversation.
Please note "Whisper" is only available as the host.