High memory usage on MacBook PRO retina 16Gb i7 2,5ghz

I'm using a MacBook Pro Retina 15-inch 16Gb Processor 2,5 Ghz Intel Core i7 Graphics Intel Iris Pro 1536 Mb OS: OS X Yoseminte v10.10.2

I'm having a problem with my ram. I think its eating too much rum when I'm not doing anything..

Please find my screenshots attached.

And this is how it looks when I have the Adobe Photoshop open (a small psd file 5,2Mb), Microsoft Word (1 page), Itunes, And the Chrome Browser (12 tabs opened)

Can someone help me with this issue? Why is it eating that much RAM? If there is any other info that you need for this situation please tell me so I can get that for you. Thank you

MacBook Pro with Retina display, OS X Yosemite (10.10.2)