Is new lubuntu 18.10 supposed to eat 700mb RAM?

[when-updtae]

bc I had no usb better than 1 GB I had to use ubuntu minimal install, and I chose only "Lubuntu-desktop" in it so it should be equal to normal install?
Idle lubuntu eats 700mb RAM and loads slower (after you enter password it struggles for some time). That makes no sence bc 18.04 used 200mb. Is it somehow related to my "minimum install" or it is features of lubuntu 18.10? How can I make it lighter? Also regarding perfomace, 18.10 introduced some tweaks so would new lubuntu still be faster than old?

[Autodave]

First of all, I would stick to 18.04 since that is a long term service (LTS) release. the 18.10 will only be supported until April of next year.

200mb sounds right, 700 way too much.

Did you install 18.10 or upgrade 18.04 to 18.10? Upgrades generally (at least in my experience) cause problems. I always do clean installs and only stick with the LTS releases.