Those are actually valid. It's a condensed code. It always uses that setup
ABBBBBBB XXXXYYYY
CCCCCCC ########
A = Code type (in this case 4)
B = Address where it starts
X = How many lines were in the original code
Y = The difference between each line.
C = Values to be used. Grandia 3 has a max capacity of 9 per item. (It's honestly better to set it to 8, so you can always continue obtaining items and not get complaints about your inventory being full)
# = Not used really, just an identifier or something? It's almost always 00000000
I actually made a few condensed codes myself for some games.
Code:
ORIGINAL:
//Fayt: Max Item Creation Skills
patch=1,EE,00501E50,extended,000000FF
patch=1,EE,00501E51,extended,000000FF
patch=1,EE,00501E52,extended,000000FF
patch=1,EE,00501E53,extended,000000FF
patch=1,EE,00501E54,extended,000000FF
patch=1,EE,00501E55,extended,000000FF
patch=1,EE,00501E56,extended,000000FF
patch=1,EE,00501E57,extended,000000FF
patch=1,EE,00501E5B,extended,000000FF
patch=1,EE,00501E5C,extended,000000FF
Condensed version:
// Fayt: Max Item Creation Skills
patch=1,EE,20501E50,extended,FFFFFFFF
patch=1,EE,20501E54,extended,FFFFFFFF
patch=1,EE,10501E5B,extended,0000FFFF
(Not a type-4 code, so it works a bit differently due to not needing the second line for values, but it's essentially the same concept).