Picture an empty map, and then people arriving on it: first the coast, then the valleys, until the blank spaces have lives in them. Two things hold that picture together. The container comes first and the contents arrive afterwards, and the filling happens over time rather than all at once. Once you can see that, the modern office use follows without any new idea: an empty table on a screen, and rows of data arriving into it until the blank space is full. Same picture, smaller container.
The source entry derives the word from Medieval Latin populatus, from Latin populus ('people'). The 'people' idea is literally inside the word, which is also why population and popular look so similar.
來源資料把這個字追到中世紀拉丁文 populatus，再到拉丁文 populus（人民）。也就是說，「人」這個意思就寫在字裡面。這也解釋了 population（人口）和 popular（受歡迎的）為什麼長得那麼像——它們是同一家。資料填入的用法是後來借畫面借過去的，不是這條字源直接帶來的。
Wiktionary/kaikki snapshot 3f6f69a190036ae4, entry 'populate' (verb), etymology_text: borrowed from Medieval Latin populatus, past participle of populor, from Latin populus ('people').
Two branches
人住進一個地方
畫面照字面用：空白的地方住上了人。
verb · B2
If people or animals populate an area, they live there. It is also used of settlers who came and filled a place, and it very often appears in the passive with words like densely or sparsely to say how many people live somewhere.
居住於；分布在
資料填進空欄位
同一個畫面換了容器：從地圖換成表格。
verb · B2
To fill a computer database, table, form or list with information. It is also used without an object, to say that the information appears by itself: 'the list populates automatically'.
（把資料）填入