Siebe: When you post things like this, please make sure to include at least a reference to the Pali version.
P.S. Thanks for sending the Pali link: Sāṇavāsīthera Petavatthu
Yes. That translation is good enough to give the basic idea.
The idea is the same as I explained above. When food is offered those types of petas can get food. When clothes are donated and merits are transferred, they can get clothes, etc.
As I explained above, there are many things that are not discernible to us, i.e., such phenomena do not happen in the human realm.
You may know about the sutta where a silver mansion appeared in a deva realm for Anathapindika, when he built and dedicated the Jetavanaramaya for the Buddha and Sangha. That was even before he died. So, the merits of that giving gave results immediately.
I would not get into these things too much. There is “no end”, and it can throw people off the main goal. This is what happens to some people who get interested in jhana. They get trapped. But of course, jhanas are not bad, if they come naturally.
It is better to spend the time in contemplating Tilakkhana and asubha nature of this world.