pls have a look at this issue:
since version 5.3.1 and with 18.104.22.168 I can not edit tables anymore.
I would like to delete my userprofile, if that might be the reason.
pls inform, where it is located (similar to %appdata%\Roaming\LibreOffice\4\user in full installation)
Within LibreOffice Portable, it's at the LibreOfficePortable\Data directory. If you delete everything within Data (copy it out somewhere else for later in case this isn't your problem), LibreOffice Portable will create a new set of default settings.
Sometimes, the impossible can become possible, if you're awesome!
deletion of profile had helped, editing tables is now possible again.