Sorry, but this isn't impressive at all... it looks like a lot of stuff but if you look at the close up shots:
http://www.idf.il/english/idf_in_pic...02/april/1.stm
One can easily make the conclusion that:
That is not a mortar. It's a single russian RPG launcher (with a shitload of ammunition, although all looks like anti-personel fragmentation. I'm not certain but i think the anti-tank HEAT version has a longer nose cone)
Three machine guns (Two Russian and a FN-SAW used by most NATO forces)
Two Assault rifles (One M-16 and a FNC or some kind of Isreali AK-clone) One of Arafats (failed) jobs was to crack down on militants, he needs this kind of weapons for his SWAT teams.
A buch of standard issue police weapons such as pistols, revolvers, shotguns and two sub-machine guns. Not surprising considering that Arafats compound is a prison rebuilt as headquarters and police station with one active prison block.
The rest is just ammo mags and single shells. Not even in any kind of quantity.
With the exception of the two machine guns and the RPG you'll find more weapons than this in your average European/American police station in a 50000-population town.
Mortars, Quassam-rocket parts and anti-tank mines would be something to show for.
This is nothing.
(And i'm not even against Israels current strategey, just trying be objective)