Put the section header (#ships classes or whatever) and make sure you put #end at the end. Make sure it is named -shp.tbm -wep.tbm or whatever else is supported. Make sure it is in Freespace/data/tables (won't work anymore else I'm told).
I've gotten ships to work perfectly (they appear at the end of the list in FRED if they are new) but weapons are a no go for me (the weapons appear at the end of the list regardless, which means player weapons are in a non-player section in FRED)
EDIT: A little pirate station based off of one of Aldo's models. You can probably just replace the model with install01.pof if you'd like to test it out in-game (tell me if it happens not to work for you)
#Ship Classes
$Name: PTI Baranec
$Short name: PStation
$Species: Terran
+Tech Description:
XSTR("Pirate station...", 3058)
$end_multi_text
$POF file: pstation01.pof
$Detail distance: (0, 3000, 8000, 10000)
$ND: 251 248 167
$ND: 255 253 196
$ND: 239 234 134
$ND: 216 212 122
$Show damage: YES
$Density: 1
$Damp: 0.2
$Rotdamp: 2.0
$Max Velocity: 0.0, 0.0, 0.0
$Rotation time: 0.0, 0.0, 0.0
$Rear Velocity: 0.0
$Forward accel: 0.0
$Forward decel: 0.0
$Slide accel: 0.0
$Slide decel: 0.0
$Expl inner rad: 150.0
$Expl outer rad: 750.0
$Expl damage: 200.0
$Expl blast: 12500.0
$Expl Propagates: YES
$Shockwave Speed: 400.0
$Shockwave Count: 3
$Default PBanks: ()
$Default SBanks: ()
$SBank Capacity: ()
$Shields: 0
$Power Output: 100.0
$Max Oclk Speed: 20.0
$Max Weapon Eng: 100.0
$Hitpoints: 80000
$Flags: ( "capital" "big damage" )
$AI Class: Captain
$Afterburner: NO
$Countermeasures: 0
$Scan time: 2000
$EngineSnd: 128
$Closeup_pos: 0.0, 0.0, -1400
$Closeup_zoom: 0.5
$Score: 200
$Subsystem: turret01,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret02,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret03,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret04,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret05,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret06,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret07,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret08,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret09,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: turret10,0.833,1.0
$Default PBanks: ( "Maxim" )
$Subsystem: awacsa,1,1.0
$Subsystem: sensorsa,1,0.0
$Subsystem: cargo1a,0.5,0.0
$Subsystem: cargo2a,0.5,0.0
$Subsystem: cargo3a,0.5,0.0
$Subsystem: strut1a,0.25,0.0
$Subsystem: strut2a,0.25,0.0
$Subsystem: strut3a,0.25,0.0
$Subsystem: strut4a,0.25,0.0
$Subsystem: strut5a,0.25,0.0
$Subsystem: strut6a,0.25,0.0
$Subsystem: engine, 5, 0.0
$Engine Wash: Default500
$Subsystem: communications, 5, 0.0
$Subsystem: sensors, 5, 0.0
$Subsystem: navigation, 5, 0.0
$Subsystem: weapons, 5, 0.0
$Subsystem: fighterbay, 5, 0.0
#End