Likely because it tied into a data dictionary from a documentation system.
The tbl01 makes it unique (so you can have a users and someone else can have theirs too), the data dictionary then tells you what fields exist in that particular table and how those fields relate to other tables.
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One company where I worked decade ago have tables numbered, like tbl01_users or tbl14_places.
Still have no idea why they establish it this way.
Likely because it tied into a data dictionary from a documentation system.
The tbl01 makes it unique (so you can have a users and someone else can have theirs too), the data dictionary then tells you what fields exist in that particular table and how those fields relate to other tables.