Could you let us know how to reduce the size of "kendo.all.min.js" (4.09 MB), kendo.bootstrap-v4.min.css (839 KB) and kendo.common.min.css (385 KB).
What I can suggest is creating a custom script bundle and including only the scripts that you need, in the link below you can find more information on how to do that:
- Creating Your Own Custom Bundles | Download and Installation | Kendo UI for jQuery | Kendo UI for jQuery (telerik.com)
I could suggest you use the Custom Builder Tool. This way you can add only the scripts needed for the used widgets and decrease the size of the scripts included.
I hope this will help you.