Make a bookmarklet out of this and you can click it to remove all videos from a page.
javascript:v=document.getElementsByTagName('video');while(v.length>0)v[0].parentNode.removeChild(v[0]);
And here's a permanent user script that will delete them as soon as the page loads
(function () {
'use strict';
window.addEventListener('DOMContentLoaded', function () {
var v = document.getElementsByTagName('video');
while (v.length > 0) {
v[0].parentNode.removeChild(v[0]);
}
});
}).call(this);