Hi I started with my project Quickstart and later changed some tables.Now there was a table Variable made by celonis, which does not work anymore because I changed some tables. How can I change this source: table variable?

You can change variables from the analysis settings.

To access it, simply click on the hamburger menu icon on the top left of your analysis screen and select variables. You should find one with the name unit_name_1, change the details and you should be good to go.