what are the most commonly used features in solidworks to model egg plate?
For a simple one, extruded boss/base, revolved cut, linear pattern (2 directions), and ironically, shell. Pretty much in that order.
It's simple by using revolved cut then multiple copies by pattern.
and you also can do it by importing a egg (3D egg design) in your plate then mate that egg on plate as per you want (can be straight / on any angle) and after it use cavity command to get egg cavity in your egg plate.