As described in this issue: https://github.com/ckeditor/ckeditor5/issues/653.
A simple fix for now will give higher priority to HTML in DataTransfer and use it instead of just taking all images from it and start uploading.
paste from word doesn't seem to preserve html tables. :(
Paste from Word isn't yet supported. And there's no support for tables too. Both things are our greatest priority right now. You can already follow the works on the table feature.
:(
Is it possible to force the editor to upload images when pasting them from the internet (like copied from the browser)?

So far, function isHtmlIncluded() prevents such insertion - the original URL of an image is used instead.
See https://github.com/ckeditor/ckeditor5-easy-image/issues/14. Please do ask such questions in tickets about another topic. Report a separate ticket in such cases.