My poor little LG Optimus Fuel (KitKat 4.4) is struggling. It only has 2 GB of on-board memory, and Google Play Services uses up 521 MB of that (over one-fourth). Is there any way to reduce the memory that Google Play Services uses?
You could try going through your Google app settings and disabling some of the functions... like the Location services, Now, etc. That might help you get some of that RAM back... you'll lose functionality, but that might be a price you are willing to pay.
Right... Google Play Services learns from your usage... the more you use the Google stuff, the more internal services it loads to access the different buckets of data.
You might want to check how much space is being taken up by all the apps provided by Google. Disabling those apps which you do not need/use should help you to reduce the space Google based apps and Google Play services occupy.