英文的動詞及and及動名詞?

第一句
He said something and ate his meal.
是從：He said something and he ate something.簡化而來的

第二句
He said something, eating his meal.
是從：He said something while he was eating something.簡化而來的

＞　是不是類似上述第一句的句型都能化簡成第二句的句型？
２句話有不同的意思．不是互相簡化而來的．

＞　這個在文法中又叫什麼？
叫做連接詞的應用．

＞　後面的動名詞句子，是變成副詞嗎?
錯，錯．不知道你在說什麼！

Having said something, he was in a atate of eating.
"eating" is the --ing form of an English verb when used as a noun(as in "in a manner of eating"; "beginning eating""=to eat in the infinitive form)