Assuming this design is for desktop application (due to the fact that the second option would not work for mobile), I prefer the second option with the blocks, because it eliminate a user click and maintains everything that is related in the field of view.
But if the task of invitations is not so important, you can leave it in the form of tabs that would work very well and will not pollute the user's screen, making it more comfortable.
Use tabs to alternate between views within the same context, not to
navigate to different areas. This is the single most important point,
because staying in place while alternating views is the reason we have
tabs in the first place.
So, just know whether it is an important task or not, to hide or make visible.
See more: https://www.nngroup.com/articles/tabs-used-right/