Here it says "Kikar Lechem." In Shmuel II, 6:19, it says "Chalas Lechem", which is smaller!
Radak (Shmuel II, 6:19): It was a Kikar, in the shape of a Chalah.
What is the meaning of "Eshpar"?
'Rashi', Rashi (Shmuel II, 6:19), from Pesachim 36b: ESHPaR is Echad of SHishah (a sixth) of a PaR (bull).
Radak (Shmuel II, 6:19): It is a part of an animal, based on how animals are normally divided. Also Yonason (there) translates so.
What is the meaning of "Ashishah"?
'Rashi', like R. Chanin (Pesachim 36b): ASHiSHaH is [a bun the volume of 72 eggs,] Echad of SHiShaH of an Eifah.
Rashi (Shmuel II, 6:19, citing Shmuel, Pesachim 36b): It is a barrel of wine.
Radak (Shmuel II, 6:19, citing Targum Yonasan there): It is a portion.
