All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The scholars stated that it is disliked for a praying person to look at any script other than the Quran. An-Nawawi said, “If a praying person looks at a script other than the Quran and recites it in his heart, his prayer is not invalidated but this is disliked. This is the view of Imaam Ash-Shaafi'ee .”
It is known that the translation of the meaning of the Quran is not considered a Quran, so it is disliked for a person who is led in prayer to look at the translation during the prayer. Holding the translation of the Quran during the prayer requires turning the pages, and this implies missing a recommended act, which is placing the right hand over the left one on one's chest. Moreover, a group of scholars are of the view that it is disliked for a praying person to hold the Quran and read it during the prayer. Some of them are even of the view that whoever does this, his prayer is invalid. So what about holding a book other than the Quran?
To conclude, it is dislikeable for a person who is led in prayer to hold and look at the translation of the Quran during the prayer on the pretext of understanding what is being recited.
Allaah Knows best.