The Table flag is crucially important for use with more advanced setups, like passing BGP traffic and routes via a wireguard tunnel, there are multiple options, auto being the default, where wireguard makes it's own table and adds routes by itself, which is fine for clients, but bad if you want BGP to make routes, the second option is to specify a specific table you want routes added to. The third option is Table = off, which adds no routes automatically, and is ideal when you are using dynamic routing engines like BGP.
Examples are below
Table = auto (or don't specify this option, this is the default)
Table = 2345 (or any table you want)
Table = off