Is it possible to add action button like ‘Comment’ associated with each row in Grid as shown below;
Sure. You’d have to use a list view instead of a data grid to model the list.
And in that list view you can add buttons. And use the bubble as an icon and no text as a caption.
When you call a microflow from that button, that row’s entity will be uses as the input parameter of the microflow and you can use that to e.g. open a page with a data view that allows to manipulate the entity and associated entities sich as “comments”.
you can try Data Grid Extension widget