Hi Susja •,
Welcome to Microsoft Q&A forum and thanks for exploring and using Azure Data Studio.
As I understand, you want to view result of different queries together so that you can compare and analyze better in ADS.
Please let us know if we understood right.
For this, you may try to enable Editor Layout to "Grid (2*2) " in View as shown below: 
Next you can execute queries with the needed changes in different sections of the Grid and could analyze results as shown below:
Currently we do have above functionality in ADS. If you want to view result in same tab, I recommend you to add your feedback over Azure Data Studio Feedback Channel where concerned team will look into this feature request and act upon depending on the importance and up-votes received.
Thanks