This problem started happened around 3 weeks ago and is very similar to the report that Tadeo submitted (MCPE-144954) I would log into my realm on my desktop and it started to progressively get more laggy (mobs suddenly didn´t move anymore, I could move and the animation for chopping executed but the items didn´t appear on my inventory until the game could load properly, it take too much time to travel with portals, etc. At first it was just a nuisance, now its doing it to the point where I can’t play or it won’t save and keep loading me in the same spot. I have tried going back to previous backups which helped for a week but it would still have some small lag. I began to pair these lags with my CPU and RAM and noticed they were directly correlated.  Other worlds on my computer are not affected and do not have the same laggy and CPU/RAM usage.  I have also lowered all the visual and chunk settings to their lowest setting or turned off and it has had no effect. I have downloaded my world from the realm to my desktop and it still is just as laggy and CPU/RAM intensive.

My Hardware

CPU                       Intel(R) Core(TM) i5-7600K CPU @ 3.80GHz   3.79 GHz
Installed Ram     16.0 GB
Disk Drive            Samsung SSD 860 EVO M.2 500GB
Video Card          NVIDIA GeForce GTX 950