Please advise

Thats how it works actually -- it takes the first X number of nodes (3 in this case) generates a title, then generates a common title for all nodes based on those

If you need something different, it's very easy to build your own 👍

on this context

document.excluded_embed_metadata_keys = ["creation_date", "last_modified_date", "file_size", "file_path", "file_extension"]

still these attributes are present in metadata.
how can i skip this

they will be included in the metadata yes.

This setting just means that they won't be included when you send nodes to the embedding model

That is what the embedding model will see