Maintenance :: Unused Partitions Take Lot Of Space And Dual Booting

So recently i bought a refurbished/used Samsung ultrabook (NP540U3C-A01UB )

One of the features is that is has : (500GB with 24GB ExpressCache - Technology)
Which I don really understand.

I've also noticed that the system has a lot of partitions that are taking space and are largely unused. I've had the computer for about a month and i use it everyday almost and so far a lot of the partitions havent been used.

I don't see a reason why to have those.

So can i Erase them??

Please notice 2 disks. I know the larger one is used for C: and the other for the ExpressCache???

Also notice that disk1 is empty. Pretty much all of them are, with the exception of 2 (C: and the partition right of it)

What is it used for?? How can i find out?? Whoever installed this system made a mess.

Here is a second part of my question:

For work reasons I have to have a Ubuntu machine and I thought I could just dualboot and use the partitions that are unused. Which is why i care about the unused space.

I have used virtualbox in the past but it was really slow. I need a responsive system and virtualization is no longer an option.

So my question would be how can i accomplish the dualbooting?? Specially taken that i have UEFI/random partitions in my system.

I know there are a lot of tutorials out there but none come close to my drive mapping/situation.

Just don't wanna destroy my system while trying to get the dualboot working.