Although it is seen in the Bible, I am sure we can find references in other Greek and Hebrew literature if one really put the effort in some database. I am from India, and I have heard the phrase "to break bread" in Hindi idioms like "to break breads for free", the idiom is used to malign someone that he is eating for free and not working or earning. So, to me, it is clear that it is an ancient Semitic or wider idiom for "eating food" or having a meal. English etymology will not give you the ancient results older than the Bible references because it is not from a modern language like English. As cited by other answer, the Wycliffe 14th century English translation might be the oldest, which too must be coming from Greek and Latin Bible. Latin phrase is frangendum panem Acts 20:7, and fractione panis Luke 24:35. It is clear the English phrase has its origin from the Scripture alone, as there couldn't have been any other older English translation of any ancient languages.
We can now trace the phrase at least to 739 and 681 B.C, which is the date of prophet Isaiah. As for the word for "break" in the Isaiah verse, the old English versions use "deal the bread" in the sense of "share" or distribute. I had to find the most literal one (SLT) to demonstrate the exact use of "break bread". I used Septuagint (LXX), the Greek Old Testament translation which goes to third century BC. The Greek word for "break" is διαθρύπτω (see the root word θρύπτω) which means to crush, break in pieces. The Hebrew word is [p̄ā·rōs] (Strong's 6536)56 here, which means to break in two, divide. Otherwise, the Greek NT, in consistency with Jeremiah 16:7, uses κλάω for "breaking" bread.