There is only one video file on your page: http://popplekharlamova.com/wp-content/uploads/2016/09/PK_VIDEO.mp4. It is being loaded on all browsers.
It’s hidden in this CSS-block as a background-image:
<style id="thb-app-inline-css" type="text/css">
.page-id-282 #wrapper div[role="main"] {background-color: !important;background-image:url(http://popplekharlamova.com/wp-content/uploads/2016/09/PK_VIDEO.mp4) !important;background-repeat: !important;background-attachment: !important;background-position: !important;background-size: !important;}.footer {background-color:#d60000 !important;background-image:url(http://popplekharlamova.com/wp-content/uploads/2017/05/BACK.jpg)
</style>
Delete it from there and you will be fine if you don’t have the knowledge to remove it from the code, then you could delete it from the folder, which will solve your problem. However, every browser will then try to load an inexisting file, which isn’t really good but won’t make any greater harm. Put it on your to-do-list and ask once some developer to delete it for you from the code.