In a spirit of inquiry and appreciation for the comments of other monks I ran all the working solutions through Time::Benchmark. Because no test is ever neutral, I've attached the script below for thems as is interested. The overall results are

10000 trials of abigail (781.550ms total), 78us/trial
10000 trials of broquaint (92.195s total), 9.220ms/trial
10000 trials of esper (676.783ms total), 67us/trial
10000 trials of ferrency (548.917ms total), 54us/trial
10000 trials of george_sherston1 (655.936ms total), 65us/trial
10000 trials of george_sherston2 (852.485ms total), 85us/trial
10000 trials of george_sherston3 (712.300ms total), 71us/trial
10000 trials of samtregar (1.303s total), 130us/trial
[download]

And here's the test script:

#! /usr/bin/perl -w
use strict;
use lib '/home/httpd/lib';

use Benchmark::Timer;
use Quantum::Superpositions; 

my %methods = (
    george_sherston1 => \&m1,
    george_sherston2 => \&m2,
    george_sherston3 => \&m3,
    broquaint => \&m4,
    abigail => \&m5,
    ferrency => \&m6,
    esper => \&m7,
    samtregar => \&m8,
);

my @tabs = (
    {
        Action => 'GetAll',
        Suppress => 0,
    },
    {
        Action => 'Make',
        Suppress => 0,
    },
    {
        Action => 'MakeOnly',
        Suppress => 0,
    },
    {
        Action => 'foo',
        Suppress => 0,
    },
    {
        Action => 'bar',
        Suppress => 0,
    },
    {
        Action => 'baz',
        Suppress => 0,
    },
    {
        Action => 'goom',
        Suppress => 0,
    },
    {
        Action => 'gomp',
        Suppress => 0,
    },
);

for my $m (sort keys %methods) {
    my $t = Benchmark::Timer->new(skip => 1);
    for(0 .. 10000) {
        $t->start($m);
        $methods{$m}->();
        $t->stop;
    }
    $t->report;
}
        
sub m1 {
    for (@tabs) {
        if (
            $_->{Action} eq 'GetAll' or
            $_->{Action} eq 'Make' or 
            $_->{Action} eq 'MakeOnly'
        ) {
            $_->{Suppress} = 1;
        }
    }
}
    
sub m2 {
    for my $hash (@tabs) {
        if (grep {$hash->{Action} eq $_} qw/
            GetAll
            Make
            MakeOnly
        /) {
            $hash->{Suppress} = 1;
        }
    }
}
    
sub m3 {
    for (@tabs) {
        if ($_->{Action} =~ /(^GetAll$)|(^Make$)|(MakeOnly$)/) {
            $_->{Suppress} = 1;
        }
    }
}
    
sub m4 {
    for (@tabs) {
        if($_->{Action} eq any( qw(GetAll Make MakeOnly) )) {
            $_->{Suppress} = 1;
        }
    }
}
    
sub m5 {
    my %match = map {$_ => 1} qw /GetAll Make MakeOnly/;
    for (@tabs) {
        $_-> {Suppress} = 1 if $match {$_-> {Action}};
    }
}
    
sub m6 {
    for (@tabs) {
        $_->{Suppress} ||= $_->{Action} =~ /^(GetAll|Make|MakeOnly)$/;
    }
}
    
sub m7 {
    my %defaults = (GetAll => 1, Make => 1, MakeOnly => 1);
    for (@tabs) {
      $_->{Suppress} = $defaults{$_->{Action}} if exists $defaults{$_-
+>{Action}};
    }
}
    
sub m8 {
    my %suppress = map { $_ => 1 } qw(GetAll Make MakeOnly);
    for (@tabs) {
       $_->{Suppress} = 1 if exists $suppress{$_};
    }
}
[download]

§ George Sherston