# tent of meeting

This is another name for the tabernacle. See how you translated this in Exodus 27:21.

# ark of the covenant decrees

"the chest containing the commandments". The ark is the chest that contains the commandments. See how you translated this in Exodus 26:33.  

# atonement lid

This is the lid that sits on top of the ark where the atonement offering was made. See how you translated this in Exodus 25:17.