"The table is not made from iron, but from plastic."
Translation:Der Tisch ist nicht aus Eisen, sondern aus Plastik.
"Der Tisch ist nicht aus Eisen sondern aus Kunststoff." is evaulated as wrong even though "Kunststoff" appears as an alternative to "Plastik".
The dictionary that you see when you hover over words is pretty terrible. If you really want to know what words are for what definition, then use a legit dictionary.
and Eisenberg= iron mountain, but i do not know the meaning of hower in Eisenhower
The original family name was Eisenhauer (an iron miner), not Eisenhower, which is a result of English "transliteration".
Do you actually need the second "aus"? The original English sentence would sound OK without the second "from".