It is very obvious that the majority of those who Israel has been killing in Gaza have been civilians. According to the Guardian:

Figures from a classified Israeli military intelligence database indicate five out of six Palestinians killed by Israeli forces in Gaza have been civilians, an extreme rate of slaughter rarely matched in recent decades of warfare.

As of May, 19 months into the war, Israeli intelligence officials listed 8,900 named fighters from Hamas and Palestinian Islamic Jihad as dead or “probably dead”, a joint investigation by the Guardian, the Israeli-Palestinian publication +972 Magazine and the Hebrew-language outlet Local Call has found.

Haaretz recently reported on how the IDF is slaughtering mainly civilians:

The IDF spokesman issued on August 20 a summary of the results of Operation Gideon’s Chariots, which began after the cease-fire with Hamas broke down on March 18 (and since transitioned into Gideon’s Chariots 1, now that Gideon’s Chariots 2 has gotten underway).

In the announcement, the IDF boasted of killing “more than 2,100 terrorists.” The statement included the names of 34 Hamas commanders or leaders during the operation. The same day, according to the Palestinian Health Ministry, 10,576 Gazans had been killed since the collapse of the cease-fire, meaning that only 20 percent of the dead were actual combatants.

In the same announcement, the IDF spokesman added, by the way, that it had staged 10,000 attacks over the period. In other words, according to the army, on average, five separate attacks resulted in the death of a single terrorist. The IDF, of course, didn’t relate to who might have been killed in the other four attacks during those six months.
An investigation published last week by the Armed Conflict Location and Event Data (ACLED), a U.S. NGO that documents violent conflicts, claimed that the number of armed terrorists killed during this period did not exceed 1,100, i.e., less than 10 percent of those killed.

An investigation published last week by the Armed Conflict Location and Event Data (ACLED), a U.S. NGO that documents violent conflicts, claimed that the number of armed terrorists killed during this period did not exceed 1,100, i.e., less than 10 percent of those killed. However, the organization doesn’t say how its number was derived.

However, the figure on the enormous proportion of civilians killed does align with an investigation from August by journalist Yuval Avraham on the +972 website and in The Guardian, based on the Military Intelligence database. The investigation found that, in May, the database recorded 8,900 Hamas and Islamic Jihad members killed or “presumed” killed. At the same time, Hamas’s death toll stood at about 53,000. This means that, according to these figures, only about 17 percent of the dead were armed or identified as Hamas members.