Hi- I saw the site and as you say, the problem is caused by table based design which the theme does not support. I would strongly urge you to switch from table based design to css tables based one using the theme shortcodes –
https://www.livemeshthemes.com/enigmatic/column-shortcodes/
and responsiveness will be taken care of automatically. Tables are considered bad for SEO by many and responsive design as well. While people have created CSS for responsive data tables (available on the web), I am not sure we have a good way to coming up with a responsive tables which can hold layouts like the ones you created. Pls have a look at the styling for the services for some examples –
https://www.livemeshthemes.com/enigmatic/services/
Let me know if you run into issues and I can help. As far as slider is concerned, doesn’t layer slider come with responsive option? You probably need to just enable it in the admin panel.