I will try to translate and explain pictures of your log book. As written from top to bottom (with originals in brackets)
PIC 1:
technical inspections (tehnicki pregledi)
date (datum)
type of inspection (vrsta pregleda) - it is written 2nd technical inspection (II. teh. pregled) in all columns
use in kilometers or working hours (rad tehnickog sredstva u km ili mc) - military logbooks were universal for rifles or for example vehicles. Here it is written SZN-M, which is type of yugo oil based cosmoline, used for 10 year storage.
comment (primedba) - it is written isp. which is short for ispravna, or flawless. Brezhibna means the same, but it is in Slovenian language, as rifle was stationed in Slovenia, most northern part of ex Yugoslavia.
signature (podpis)