Unfortunately, not all plotting functions accept table variables in MATLAB yet (scatter was one of the first of the 'traditional' plotting functions that we added table support to in R2021b).
So for the time being, you can use plot (I strongly recommend that over line), but you'll need to specify the values rather than the table variables. Your code would look like:
daten = readtable("datasetexperiment1.csv");
scatter(daten,"Times","vms");
hold on
plot(daten.Times, daten.vms);
Note that plot can also include markers, so you could just do:
daten = readtable("datasetexperiment1.csv");
plot(daten.Times, daten.vms,'-o');
