After returning home, my kids had leftovers on the table so I ate it all.
「帰宅後、食卓に子供達の夕飯の残りがあったので全て食べた」は英訳すれば、「After returning home, I ate all the leftovers that my kids left on the table.」になります。
まず「After returning home」は「帰宅後」という意味です。
そして、「my kids had leftovers on the table」は「食卓に子供達の夕飯の残りがあった」とう意味です。最後に「so I ate it all」は「~ので全て食べた」を表します。
ご参考になれば幸いです。
"When I got home, there were leftovers from my kids' dinner on the table, so I ate them all."
"When I got home, there were leftovers from my kids' dinner on the table, so I ate them all."
"When I got home, I found my kids' leftover dinner on the table and finished it."
"I ended up eating all the leftovers from my kids' dinner."
① 帰宅後(when I got home / after I got home)
② 子供達の夕飯の残り(leftovers from my kids' dinner)
③ 全て食べた(ate them all / finished it / ate all of it)
特に「夕飯の残り」は leftovers という単語がとても自然です。
leftover ではなく、leftovers と複数形で使うのがポイントです。
「食べ残し」「残り物」という意味になります。