Keiko efficiently stacks the dishes and carries them to the sink.

Literal

Keiko [subject-が] efficiently dishes [object-を] stacks-[and-て], sink [toward-へ] carries-[continuing-ていく].

Narrative present tense. 手際よく ('efficiently, skillfully') is a set adverbial phrase. 手際 ('skill, dexterity,' literally 'hand-edge') + よく ('well') = 'well-skilled.' ~てゆく is a slightly more literary variant of ~ていく (same meaning — motion away, continuation forward). 食器 ('tableware, dishes').