Microsoft Excel

I don't think this will be a straightforward answer...

There is an old version of Excel which had a maximum of 65000 rows. That was a while ago. The current version has over 1 million rows.

By best guess on what is happening is:

the export from Oracle refers to an older version of excel, hence the reduced number of rows.

So i think you have two options:

First but more manual: copy the second sheet data and add that to your first sheet so everything is in one worksheet

Second: speak to your Oracle administrators to see if they can see what is happening on their end. As the data is coming out of Oracle then the settings within Oracle will be controlling what happens to the format of the data.
It's a long time since I've worked with exports from data bases but it could be - I do not know this for sure - that Oracle just needs a newer link to excel. I would ask you Oracle people about this.

Please let us know how you get on.

thanks
Claire