You can give it CSS properties of width and height equal to 100% by using sizing classes .w-100 and .h-100 https://mdbootstrap.com/docs/standard/utilities/sizing/

Here is the snippet: https://mdbootstrap.com/snippets/standard/m-duszak/3721470#html-tab-view

However parent of this element in the snippet has 0 height and dynamic width of what .col-lg-6 gives it. If you want it to fill all the available viewport to create somewhat like a background, you can take it out of your .container element and style it properly.

Here is the snippet: https://mdbootstrap.com/snippets/standard/m-duszak/3721495