This isn't high RAM usage by vanilla Ubuntu 16.04 standards in my experience. I run Ubuntu 16.04 on a desktop computer that has plenty of RAM and I'd say this usage is par for the course.
However, my laptop has very similar specs to what you've listed (2GB RAM, etc.), so for my laptop I use Ubuntu MATE 16.04, which in my experience tends to use ~350MB less RAM from startup than vanilla Ubuntu.
For lower end hardware like this, I highly suggest going with either the Ubuntu MATE, Xubuntu, or Lubuntu flavors that have lighter desktop environments than Unity. Xubuntu and Lubuntu are even lighter than Ubuntu MATE, but I just really like the MATE DE and prefer it to XFCE (used by Xubunut) or LXDE (used by Lubuntu).
I must mention that MichaelBay is right -- no matter what flavor you go with, modern browsers are RAM hogs, so switching to MATE or Xubuntu won't really change that aspect of it, you just end up using less total RAM due to the lighter DE.
top
command in terminal to see RAM eaters programs.