I have MS Access File with a file size of 1.7GB. I have already tried to compact and repair, but the file size remains the same.
This is what I did. I download about 29 files from jupyter python to excel and csv files. The total amount of data is about 934MB.
I need to update the data everyday, therefore I linked the Access file to all the exported files under linked table and create another table to have a relationship with each other. So I have 2 tables for each exported file, for example: customer_linked and customer.
And this is the step by step of query:
1. Delete query for all data in non-linked table
2. Append query to append the linked-table to non-linked table
I have no idea that this way, it will make the file super bloated to 1.7GB. Is there any way to make it smaller?
Surprisingly the file in csv take more space than the file in excel.

No surprise if that is an .xlsx file, as these are zip files. Try renaming it to .zip and unpack it to see the real size.
If you have compacted it, that is the size - Nothing to worry about.
The only concern could be, that you are approaching the size limit of 2GB for an Access file. If that could hit you, consider moving data to, say, the free SQL Server Express edition which allows for 10GB.
MS Access Big File Size Problem with exported file from Python