Dear @myy5028,
The meaning of the data in the bnn.lis file is explained in the Fluka manual at the USRBIN page and the reference therin.
Additionally, a question similar to your has already been discussed in this thread on the forum.
Last, (1(5x,1p,10(1x,e11.4))) is standard Fortran syntax that you can understand reading any Fortran manual or searching online.