Excel sheet takes up a lot of memory
<p>I designed a tool in Excel that contains a sheet that acts as a user input form.</p>

<p>On the sheet is an active-x combo box, eight shapes with assigned macros, and a range formatted with colour and borders to display data.</p>

<p>This sheet takes up around 3Mb of memory. I made a copy and after deleting this sheet the file size drops to around 200Kb and everything is much smoother.</p>

<p>So far I have tried:</p>

<ul>
<li>Unhiding all rows/columns and filling all cells in with "No fill"</li>
<li>Eliminating excessive formatting tool (Inquire tab on the ribbon)</li>
<li>Deleting all shapes/combo box one by one</li>
<li>Removing borders and all text</li>
<li>'Demerging' all merged cells</li>
<li>Removing unused styles</li>
<li>Removing conditional formatting</li>
</ul>

<p>I was left with a completely blank sheet, and still after deleting the sheet the file size dropped by 3MB.</p>

<p>Why might this  be happening?</p>