The customer sitting next to me at a restaurant spilled his tea all over me.
Someone sitting next to me at a restaurant knocked his tea over and it splashed on me.
どちらも「レストランの隣に座っていた人にお茶をかけられた。」という言い方です。
1) The customer sitting next to me at a restaurant spilled his tea all over me.
spill で「こぼす」
all over me で「私の体中に」
＊お茶が結構かかった時にこのように言えます。
2) Someone sitting next to me at a restaurant knocked his tea over and it splashed on me.
knock ... over で「…をひっくり返す」
splash on ... で「…にはねかける」
＊こちらははねかかった程度の場合使える言い方です。
ご参考になれば幸いです！
日本 
