Welcome to the community, @Jack_Lu! :grinning_face_with_big_eyes: No matter which way you go, it’s going to be a slow process to import that many records. I’ve got one client with over 21K records in each of several bases, and there’s a noticeable delay just in opening any base of that size, let alone adding data to it.
Airtable’s data structure is very different from a spreadsheet, and the way that Airtable syncs data to its servers might also be one of the factors behind the speed (or lack thereof). I recommend reaching out to Airtable support directly (in the app: Help → Contact support) for a more precise answer to your question. While Airtable staffers do frequent the forum, they prefer to be approached directly with support requests, and this feels like it’s shifting in that direction.