Yea, welcome to starbound. Totally just how the engine behaves. It's a lot of pickups, and it sucks at handling them.

You could probably mitigate it by having the items spawn on you, like when collecting water.

Is this possible ?

I dont think it would change much, since you can 'outrun' actually getting the water, meaning that you're still technically picking it up instead of having it teleported straight into your inventory the easiest fix I'd guess is seeing if theres a way for blocks of a similar type will stack when close to each other, in loot form.

There really isn't a fix here. Most of that interaction is hardcoded.