The following parses the data into a structure somewhat like the one you describe. It doesn't insert extranious single element arrays and it is not robust against nested quoted strings, but it may be a useful starting point for your actual application.

use warnings;
use strict;
use Data::Dump::Streamer;

my @libs;

local $/ = 'libname='; # Read a record at a time

while (<DATA>) {
    chomp;
    
    next if ! length; # Skip blank lines
    s/\n|\r/ /g; # Remove conventional line end characters
    
    next if ! s/(\S+)\s*//;
    
    my $str = $_;
    my %record;
    
    $record{libname} = $1;
    
     while ($str =~ /=/) {
        # Process an option
        last if ! ($str =~ s/\s*(\S+?)\s*=\s*//);
        my $opName = $1;
        my $opValue;
        
        if ($str =~ s/^\s*"([^"]*)"\s*//) {
            # Complicated option value
            $opValue = parseSubOps ($1);
        } elsif ($str =~ s/\s*(\S+)\s*//) {
            # Simple option
            $opValue = $1;
        }
        
        $record{$opName} = $opValue;
    }
     
    push @libs, {%record};
}

Dump (\@libs);


sub parseSubOps {
    my $str = shift;
    my %subOps;
    
    while ($str =~ /=/) {
        # Process a sub-option
        last if ! ($str =~ s/\s*(\S+)\s* = \s*\(\s* ([^)]*?) \)\s*//x)
+;
        my $name = $1;
        my @values = $2 =~ /'([^']*?)'/g;
        $subOps{$name} = \@values;
    }
    
    return \%subOps;
}

__DATA__
libname=foo pathname=/path/to/metadata/foo owner=someuser libaclinheri
+t=no dynlock=no
   roptions="
       datapath=('/data/path1'
                 '/data/path2'
                 '/data/path3'
                 ...)
       indexpath=('/indx/path1'
                  '/indx/path2'
                  '/indx/path3'
                  ...)
       workpath=('/work/path1'
                 '/work/path2'
                 '/work/path3'
                 ...)
       metapath=('/meta/path1'
                 '/meta/path2'
                 '/meta/path3'
                 ...)";

libname=bar pathname=/path/to/metadata/bar owner=someuser libaclinheri
+t=no dynlock=no
   roptions="
       datapath=('/data/path1'
                 '/data/path2'
                 '/data/path3'
                 ...)
       indexpath=('/indx/path1'
                  '/indx/path2'
                  '/indx/path3'
                  ...)
       workpath=('/work/path1'
                 '/work/path2'
                 '/work/path3'
                 ...)
       metapath=('/meta/path1'
                 '/meta/path2'
                 '/meta/path3'
                 ...)";

libname=foobar pathname=/path/to/metadata;
[download]

Prints:

$ARRAY1 = [
            {
              dynlock  => 'no',
              libaclinherit
                       => 'no',
              libname  => 'foo',
              owner    => 'someuser',
              pathname => '/path/to/metadata/foo',
              roptions => {
                            datapath  => [
                                           '/data/path1',
                                           '/data/path2',
                                           '/data/path3'
                                         ],
                            indexpath => [
                                           '/indx/path1',
                                           '/indx/path2',
                                           '/indx/path3'
                                         ],
                            metapath  => [
                                           '/meta/path1',
                                           '/meta/path2',
                                           '/meta/path3'
                                         ],
                            workpath  => [
                                           '/work/path1',
                                           '/work/path2',
                                           '/work/path3'
                                         ]
                          }
            },
            {
              dynlock  => 'no',
              libaclinherit
                       => 'no',
              libname  => 'bar',
              owner    => 'someuser',
              pathname => '/path/to/metadata/bar',
              roptions => {
                            datapath  => [
                                           '/data/path1',
                                           '/data/path2',
                                           '/data/path3'
                                         ],
                            indexpath => [
                                           '/indx/path1',
                                           '/indx/path2',
                                           '/indx/path3'
                                         ],
                            metapath  => [
                                           '/meta/path1',
                                           '/meta/path2',
                                           '/meta/path3'
                                         ],
                            workpath  => [
                                           '/work/path1',
                                           '/work/path2',
                                           '/work/path3'
                                         ]
                          }
            },
            {
              libname  => 'foobar',
              pathname => '/path/to/metadata;'
            }
          ];
[download]