Targeting civilians vs civilian casualties
Putting aside numbers for a bit, the context here is clear. The 7th October massacre specifically targeted civilians for gruesome torture, murder, and kidnapping:
According to documents recovered from the bodies of killed militants, militants were instructed to attack civilian populations, including elementary schools and a youth center, to "kill as many people as possible", and to take hostages for use in future negotiations.
We have video evidence of this:
Other videos show attackers shooting at children, executing men in civilian clothing, throwing grenades into civilian shelters, and decapitations.
That's also the reason given in a joint statement why the US, France, Germany, Italy, and the UK consider it a terrorist attack:
In recent days, the world has watched in horror as Hamas terrorists massacred families in their homes, slaughtered over 200 young people enjoying a music festival, and kidnapped elderly women, children, and entire families, who are now being held as hostages.
Specifically targeting civilians. That's a terror attack.
Operation Protective Edge was a military operation to stop rockets being fired at civilian infrastructure. It included air strikes targeting military infrastructure as well as a ground invasion. It did not purposefully target civilians.
Targeting military infrastructure while accepting civilian casualties. That's a military operation.
The numbers
Now, looking at the numbers:
At least 1,400 Israelis were killed, including 1,033 civilians,[13] 275 soldiers[14] and 58 police officers.[8]
Police officers are generally considered civilian casualties unless they take part in military actions.
That gives us a civilian death rate of 73% for the Hamas terrorist attack (the civilians were the target, the soldiers were just accidental casualties).
For Operation Protective Edge we have calculations ranging from 65% civilians (from the anti-Israel UN HRC, based partially on numbers from the Hamas-controlled Ministry of Health in Gaza) to 36% (from Israel).
Civilian deaths vary widely between different wars. Some claim rates as high as 74% starting in the 80s, up to 90% in the 90s. Others claim averages of 50%.
For different wars, see eg Estimating the Number of Civilian Casualties in Modern Armed Conflicts–A Systematic Review. The Korean War eg has 74%, Vietnam 46%, the first Persian Gulf War 87%, the Yugoslavian wars 52-56%.
In a war where one party specifically hides its military operations under civilian infrastructure to use it as human shields, a higher than average civilian death rate can be expected.