In PCB editor there are footprint value for each components which belongs to layer ‘‘F.Fab’’, will these contents also be printed on the PCB board during manufacture ? Should I also avoid the components while placing them (like Footprint reference in Silkscreen layer)?
Fab layers are just notes and will not be manufactured. I never submit them. You can turn off their visibility in the layer controls.
BTW a search would have found you answers. For example this one: pcb design - What is the Fab layer used for (PCB)? - Electrical Engineering Stack Exchange
The Fab layer is not needed for the fab house, but it is handy for me when I am hand-soldering as the refdes and values are all on one sheet. I print it out and then use colored pencils to make the parts that have a lot of the same value (eg: 0.1uF yellow, 10uF orange, 10k blue…), Then I turn on some standup comedy in the background and fire up the soldering iron If I have time, I get JLC to put the garden-variety parts on, so I have less to solder.