Save as .raw in Photoshop. Except for game palettes, the images should use a 256 colors table.
Use "offset" for multiple palettes in a single file.
The shade table is set for each individual palette, unless you use "noshades".
Game palette
basepalette 0 { raw { file "basepalette.raw" } }
basepalette 1 { raw { file "basepalette.raw" offset 768 } }
Blend table
blendtable 0 { raw { file "blendtable.raw" } }
blendtable 1 { raw { file "blendtable.raw" offset 65536 } }
Lookup palette
palookup 1 { raw { file "palookup.raw" } }
palookup 2 { raw { file "palookup.raw" offset 256 } }
palookup 3 { raw { file "palookup.raw" offset 512 noshades } }