Starting a

In the lobby, between the table list (top left) and the players list (bottom right, you'll find the "Start a table" button

Click on the button and select your table settings

The Min and Max rating, will protect your table from anyone sitting outside your selected rating preference.

When starting a table you become the owner of the table.
Should you be disconnected, the ownership will automatically be bestowed to another player at that table and the table continuous to exist until all 4 players have left.