I check all my deleted post. I’m sure that it's not a spam because it's same quality on all of my post. I notice that this an attack because all the reported post was made a month ago and its in consecutive order.
But fact of the matter is quality posts usually never get deleted unless off topic or spammy..and fyi length of a chart doesnt guarantee quality , and btw why would you say this is an attack on you...do you have a reason for this to happen to you??
If you are in a paid signature, chances are high that posts are looked at keenly for that quality check and this isnt a new venture.