I try to avoid using Libre Office on existing Excel created workbooks because of the potential for unpleasant results. In this case Libre Office bloated the size of the workbook for some reason unknown to me. I would like to know if Libre Office does this to all Excel workbooks or just something in that workbook that causes it.

Software involved:

• Microsoft Office Excel 2010
• Libre Office 3.5.x (exact version unknown)
• Dropbox (merely to sync changes)

Platforms involved:

• Office on Windows (master of the obvious on that one I suppose..)
• Libre Office on Mac OS 10.6

Types of data stored in this workbook:

• Text
• Integers
• 1 column with a simple formula spanning the entire worksheet representing that particular row (=CONCATENATE(A2285,B2285,D2285), =CONCATENATE(A2286,B2286,D2286), etc.)
• Total of 3,500 plus rows

Here is a photo with details described within, but I'll go ahead and explain the photo as well:

• This screenshot is from Dropbox history of the .xlsx workbook.
• Version 61 - 68 were Office Excel.
• Version 69 - 73 were Libre Office.