Inrush current in Apk/us what does it mean
Yes, the specification is for inrush current.  

If you look at section 3.8 of the data sheet you reference, the manufacturer calls for a type CCMR fuse (Little Fuse brand).  LittleFuse mentions "withstand sustained starting currents".

  

http://www.littelfuse.com/~/media/electrical/datasheets/fuses/industrial-and-ul-fuses/littelfuse_fuse_ccmr_datasheet.pdf