Hello @PawelPablo,
there are Save icons in the upper left corner of KNIME if that is what you are looking for.
Also there is Auto save option which can be configured from within KNIME if you go:
File --> Preferences --> KNIME --> KNIME GUI
Regarding off topic question. There is option in Excel Writer to Open file after execution but I’m afraid this will only work for local files. See here for more on that and a workaround:
Br,
Ivan