Origin of the word "Blatting"

Solution 1:

Eric Raymond, The New Hacker's Dictionary, third edition (1996) has this entry for blat:

blat n. 1. Syn. blast, sense 1 ["v.,n. Synonym for BLT {'to copy a large array of bits from one part of a computer's memory to another part, particularly when the memory is being used to determine what is shown on a display screen'}, used esp. for large data sends over a network or comm line. Opposite of snarf. Usage: Uncommon. The variant 'blat' has been reported"]. 2. See thud ["Yet another metasyntactic variable (see foo). It is reported that at CMU {Carnegie Mellon University} from the mid-1970s the canonical series of these was 'foo', 'bar', 'thud', 'blat'."].

Whether these meanings have any connection to the particular usage that the poster asks about is dubious. I imagine that any onomatopoeic sounds that suggest either farting or belching are likely to have emerged independently multiple times in the argot of computing. Still, it isn't a very large step from copying/pasting or transferring a large array of bits to deleting them. I've done it myself.