DB Files

I created a  new table (V16) and then used SimplySql to take data from mssql to the new Postgres table. The table is 212gig in size. Myquestion comes from the files created on the OS(Windows2022 server) I can see lots of files with the last being:

2474695.143

They are all 1,048,576kb 

Is this normal behaviour and could I have done something to use fewer files and larger ones?


This table is created in a separate tablespace on a dedicated drive on the windows file system.

 I'm just getting involved in this PostgreSql instance 

THanks.