The traders were returning to their neighbourhood after buying vegetables from the wholesale market in Manikganj’s Jaagir.
Dhaka Metropolitan Sessions Judge Md Kamrul Hossain Molla framed charges on Tuesday and fixed Nov 24 to hear witnesses' testimonies.
Aid worker Tavella was shot dead in Dhaka’s diplomatic enclave, Gulshan, on Sept 28 last year.
Police arrested four suspects on Oct 24-- Rasel Chowdhury, Tamzid Ahmed,Minhazul Arefin and Shakhawat Hossain--all of whom confessed to the killing in their statements recorded in court.
The fifth suspect, BNP leader MA Kayum’s brother, Abdul Matin, was arrested on Nov 4 last year from the border town of Benapole in Jessore.
Police pressed charges against seven people, including the five already arrested.
The two others, Kayum and Md Sohel, are still on the run.