HI,
We can make use of dialog-ready event to manipulate dialog fields when we open a dialog.
However the use case of populating it with page title will not be possible as the same is not accessible in front end.
Perhaps we can make use of window.location.pathname to get pagename alone by string manipulations. (If page name is framed automatically or if it is consistent across projects, you can arrive at way of making extracted page name as Page title, again via String manipulations)
$(document).on("dialog-ready", function() {
var pageTitle = ..
$("input[name='./text']").val(pageTitle); // name attribute of desired dialog field
});