Any "Inviter" and "Manager" of a club can go to either the "Games" or "Tournaments" tab and click "Copy Invitation Link" on the far right of a table's row.
This link can be sent to a non-member, who will then be asked to choose a club username and then taken directly to that table or mtt lobby.
A second option is to create an invitation link in the Members tab that will redirect the invited person to the club page.