Reproducible in Chrome and IE11. In Firefox highlighting a row and applying formatting (bold) applies it only to the first cell on the row.
strong tags are added under the tr element
strong tags are added only under the td elements.
On MAC, command+c cut instead of copy when selected texts are in a table. To duplicate, please follow these steps.
1. Go here: https://demos.telerik.com/aspnet-mvc/editor
2. Insert a new table.
3. Add some text into the table.
4. Select texts in the table.
5. Press command+c on MAC.