The wiki pages you need to edit are:
http://doom.chaosforge.org/wiki/index.php?title=Template:MWeaponshttp://doom.chaosforge.org/wiki/index.php?title=Template:Weaponshttp://doom.chaosforge.org/wiki/index.php?title=Template:ItemsDo note of the syntax, it goes as follows (comments bolded, and after //):
{| style="border: 2px solid darkred; border-spacing: 0; float: left; font-size: 90%; margin: 0.25em 0.5em; width: 70%"
//Introductionary stuff, don't touch|colspan=2 style="background: darkred; color: yellow; font-size: 120%; text-align: center"|'''{{{weapon_name}}}'''
|-
//Table name i.e. weapon name in this cease - again leave it as it is.|style="text-align: right; width: 12em; vertical-align:top"|'''Damage:'''
|style="padding-left: 1ex"|{{{weapon_dmg}}}
|- style="background: #333;"
//Do note the style=background thing, this is important - rows to alternate between dark grey and light grey you need this appear every other line - essentially the three lines above are one row in the table - copy-paste those and remember to fix style=background stuff afterwards.|style="text-align: right; width: 12em; vertical-align:top"|'''Average Damage:'''
|style="padding-left: 1ex"|{{{weapon_avgdmg}}}
|-
//And the second row, no style=background here. Another note - the place where you have '''Average Damage:''' is where you put the row's description, and {{{weapon_avgdmg}}} is the ID that will be used to fill in the table(...)
|-{{#if:{{{weapon_source|}}}|
{{!}}style="text-align: right; width: 12em; vertical-align:top"{{!}}'''Source:'''
{{!}}style="padding-left: 1ex"{{!}}{{{weapon_source}}}
{{!}}-}}
|}
//And the above consists of end of the table and hack that Kornel made to make Source field appear only when used. Best left untouched.Hope that helps.
PS. Oh, and please do backup the code of the tables before changing anything in cease anything goes wrong :P