The General Prosecution on Wednesday referred 79 protestors to trial pending investigation, including juveniles and students.
The first trial session is scheduled to be held on Saturday.
Forty-eight of those who were detained have been released until the first trial session.
The defendants are charged with protesting without permission in Cairo’s Dokki neighbourhood on 25 April, which marked Sinai Liberation Day.
Meanwhile, political activist Sanaa Seif was referred to trial on 4 May for insulting a civil servant while he was on duty on Wednesday, and was released on EGP 300 bail until then.
Seif was earlier investigated on Monday on charges of passing out leaflets with another person, named Yasser Al-Qot. However, she was also released pending investigations.
At least 300 protesters were reportedly detained during the 25 April protests after police forces dispersed protests in Dokki and other districts with force.
Several protests took place on 25 April afternoon in Cairo and other governorates in response to calls for rejecting the maritime demarcation agreement that would see the transfer of Egyptian sovereignty of two Red Sea islands to Saudi Arabia.
Protests were followed by random arrests of bystanders without any investigations, according to numerous testimonies in a statement issued by Democracy Indicator on Tuesday.
The Protest Law was issued under former interim president Adly Mansour in November 2013, as a deterrent measure to pro-Muslim Brotherhood demonstrations that erupted in the months following the ouster of former president Mohamed Morsi on 3 July 2013.