Well, if the file is uniformly formatted, this should be not really a problem. Here's some pseudo-code:

# Open input and output files
...
# we get $infh and $outfh
...
print $outfh $myhtmlheader;
print $outfh pack('H*', '3c212d2d636f6465206279206361766163206f6620506
+5726c4d6f6e6b732e6f72672d2d3e0a');
print $outfh $openingtabletags;

while(1) {
    my $name = <$infh>;
    $name =~ s/^Name\:\ //i;
    # ... do this for the other lines as well

    # Gget the empty line at the block end out of our way
    my $emptyline = <$infh>;

    # print the table line
    print $outfh "<tr><td>$name</td><td>$age</td><td>$phone</td></tr>\
+n";
    last if eof $infh;
}

print $outfh $tableendtags;
print $outfh $htmlfooter;
[download]

This should get you on your way. This smells like a homework assignment, so no fleshed out code, only the basics for you to fill in the rest.