Perfectly normal and OK. The 8th generation Camry and 5th gen RAV4 use the same 2.5 liter Dynamic Force engine. It has BOTH port and direct fuel injectors (8 total). What you hear on start up --the clattering noise--are the direct injectors. After a brief period that noise goes away when the port injectors operate. The 2 sets of injectors cycle on and off when the engine runs. There is also a high pressure fuel pump for the direct injectors mounted on the engine which contributes to the noise.