Question: I have a table with a list of companies (only the most important properties):
[![enter image description here](https://i.stack.imgur.com/OElgH.png)](https://i.stack.imgur.com/OElgH.png)

There is more data for each company, including another list of Licenses.

To expand that company details, should I use:

1. New **tab**?

[![enter image description here](https://i.stack.imgur.com/jJYMv.png)](https://i.stack.imgur.com/jJYMv.png)

A new tab will be added with the company name as the tab title, inside that tab I would have some details and a list of products. Users can go back to the main tab, choose another company and have a few company details tabs open (for example 3). The tabs can be closed.

2. **Accordion**:

[![enter image description here](https://i.stack.imgur.com/nJ3bq.png)](https://i.stack.imgur.com/nJ3bq.png)

Similarly, as above, the accordion would have some details plus a list of products

3. Maybe **popup** screen that would cover 90% + of the screen.
4. Or there is better option?

I'm trying to figure out what is best for the user.

Answer: 
Both ways work, so that is not an issue.  

Take a closer look at how your users work with the table:

* Do they only open the details to glance at them and then go on to other entries? - Then the accordion would be the better option.
* Do they open dsome entries from the list and then work within the details with few need to go back to the list of companies until finished? - in that case using tabs may be the better option

Content in different tabs is quite strongly encapsuled and separate from the rest.   

Content in an accordion is very close and accessible, but: if there is a lot of content it may be difficult to keep the overall structure in mind, the users lose context while they scroll and do not see the parent list any more.
If you are in a browser you should most likely open a native-browser tab, since the user is familiar with those. The user can place multiple browser windows on multiple monitors and arrange them however he likes, or even save tabs as bookmarks.

The main benefit of an accordion is if you want to quickly show the details of many companies besides each other. If this is a valid use case an accordion could be good option. If the users are not comparing multiple companies in the list, an accordion will most likely bring no real benefits over native tabs.