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.
As a user, I would prefer accordion as the primary UI for seeing company details. I'm just not sure if it should be exclusive, or should multiple ones be allowed to be open at the same time.

Multiple open at the same time would allow search + cross-comparison, using browser-native functionality. But it might get a bit overwhelming. Perhaps allow multiple open, but have an easy "collapse all" option somewhere?

I would only want tab if I wanted to cross-reference multiple companies. But in that case, I'd prefer a browser native tab, which I can move side-by-side with a different company, bookmark, share a link, etc.

Popup could also work, but I find that popup is like "the final frontier". You can only get there once, and then you're stuck. Eg. if you decided to add a little interaction with a company that requires a popup of its own, you'd have to pile two modals one on top of another, which is bad.

Of course, all these opinions are contingent on what kind of audience you have. My preferences are those of a tech-competent power user. If you have a lot of older tech-illiterate folk, for example, then maybe a popup would be the least confusing for them.