[Shadow Stranger]

File GMDATA.PAK.
This file controls town quests, shops and guilds.
It has a size of 175,514 Bytes.

Offsets 0 to 776: The Table of Contents
Each section is represented by eight bytes, the first four list the starting offset while the second four give the length of the section.

Section 0: Some basic words
0 776 (?, Hail, Goodbye, Trade, Gael Serran, Crypt, Graveyard, Gareth, Serpent Temple, Nymph Lake)

Sections 2 to 22: the code behind the dialogs:
2 912 Sir Elgar
3 2,152 Onabe
4 4,000 Smitty
5 5,976 Roendalf
6 7,713 Galliwag
7 8,797 Master Wu
8 10,632 Bratsol
9 12,525 Lord Barrenhawk
10 13,865 Munsey
11 15,737 Damosh
12 17,784 Xander
13 19,548 Alonso
14 20,644 Sinsei Asami
15 22,685 Miruth
16 24,601 Duke Brinsly
17 25,668 Malakai
18 27,683 Strumbold
19 29,804 Sabastio
20 31,654 Holthorne
21 32,466 Buckly
22 32,983 Gareth's Dream

Sections 34 to 54, the actual dialog.
34 33,100 Sir Elgar
35 38,472 Onabe
36 46,662 Smitty
37 53,997 Roendalf
38 61,049 Galliwag
39 65,932 Master Wu
40 73,621 Bratsol
41 82,079 Lord Barrenhawk
42 88,611 Munsey
43 96,777 Damosh
44 104,424 Xander
45 111,864 Alonso
46 116,880 Sinsei Asami
47 125,900 Miruth
48 134,497 Duke Brinsly
49 139,850 Malakai
50 149,837 Strumbold
51 158,422 Sabastio
52 167,587 Holthorne
53 170,798 Buckly
54 172,263 Gareth's Dream

66 173,750
66 through 86, all sections are identical.
86 175,430

Explanation:
2 912 Sir Elgar
2 is the section number, 912 is the start offset and Sir Elgar is the subject of the section.

Sections 34 through 54 have tables of contents, that enable you to see what starts where. But then all dialog is separated by a 0 anyway.
My understanding of the code sections is fairly poor, I can spot item numbers that is about it. Decryption would normally be hard going indeed. But there are possible workarounds. Guilds have some classes handled in each guild but not all classes, this can be used to some effect. It is clear what classes should be found in each guild and what classes should not be.