expression
this and that; one thing and another
Used when referring to various things or topics in a casual, non-exhaustive way. Often implies a mix of items or matters.
あれやこれやと忙しくて、返事が遅くなった。
I was busy with this and that, so my reply was late.
あれやこれや考えすぎて、決められない
I'm thinking about one thing and another too much and can't decide.