.xlsm and .ods.
Both of them are .zip archives really. Rename two copies of the files to .zip filename extension, and then unzip them. Then you will able to check the contents, and the size of the contents.
Unzipped the files into ODS and XLMS folders.
XLMS is 8.9 MB, 138 files, 11 folders. Seems reasonable.
ODS is 34.4 MB, 303 files, 86 folders. Seems unnecessarily large.
What stands out most in the ODS extraction is 66 object folders (Object 1 - 66: 3.37 MB, 198 files, 66 folders) and ObjectReplacements folder (19.9 MB, 66 files, 0 folders).
Remaining is 11.1 MB, 39 files, 19 folders.
The big offender is the object replacements. Whatever those are.
Here’s an approximate description of the workbook.
dozen sheets
Per sheet:
200 rows by 20 columns of data
dozen merged cells per row
6 charts per sheet
2 form control push buttons
Macros:
6 macro modules (~2000 lines)
1 dialog module
Save as:
xlsm: 1343 KB
ods: 3397 KB
LibreOffice 7.6.6.3