I would like to label the points of my point layer with the name attributes of the surrounding line features. The result should be a list, with the names of all lines next to the point (f.e. 10 map units). In the screenshot you can see, which result I do expect.
Assuming all your line features are on the same layer, try
in the label expression for your point feature.
Change 10 to whatever distance you want to pick up features from, and \n to whatever you want to delimit each line name with (comma, full stop, comma+newline...)
Note however it comes in order of the line featureid and not the value of "line_name_field".