Summary

In the old editing experience, it was possible to use the intention buttons in the top toolbar to indent text within tables or in the page at all - this is no longer an option for when we want to insert indentation on our text withing a table.
Hitting the TAB keyboard key only works for content that is not inside a table. Hitting TAB from withing a table leads you to the next cell.

Suggestion

Adding a button that allows you to add text indentation inside table cells.