There is just one page per category, yes. However, there's more than enough room to hold one piece of the highest level for each and every job. Even in the Main hand category.
I too found it a bit cluttered at first, but after a while you realize that due to level synch you wont be using any of the lower level weapons ever again anyhow. You can simply turn them into Materia and keep only the one with the appropriate level for you, or simply toss/sell them to a npc. There really will be plenty of space that way.