When I started my IT career - some time ago! - DEC (Digital Equipment Corporation, makers of PDP and VAX) advised that it was computationally infeasible to crack any password with more than 6 characters at the time.
These days, nobody brute forces passwords, which is what the table refers to. Instead they use "Rainbow Tables" - effectively pre-compiled complete lists of encrypted passwords, which can be searched much more quickly than brute forcing. Hence use of Multi-Factor authentication for most sensitive uses.