When the scrollable option is disabled, on resizing the browser window by making it more narrow, at certain point the columns stop resizing and the whole table goes out of the right border of the Grid. Reproducible with the SASS and LESS themes.
Dojo example: https://dojo.telerik.com/ItIrEzEY/3
The table goes out of wrapping element (.k-grid).
The columns resize and the table remains within the borders of the Grid.