Hi Salson,
The short answer to your question of making memo fields searchable is that it isn't currently supported in Method. What you can do however, is build a table and add a custom field "memo" that and use the filter the contents to simulate the search feature.Down the road we will definitely be looking into extending Method with this functionality, however do not have a time frame for this.
In general, it is best practise to use the 'memo field' as an "additional notes" field, and store key data such as PO #'s in separate custom fields, so that you can use that data operationally.
Also, regarding exporting to excel from Method, if you go to the
Customize tab -> Integration Tools, you will find an Import/Export
tool that allows you to export all data from any table to an Excel
spreadsheet, and conversely, import such spreadsheets (provided they are
formatted correctly) back into Method.
Hope this helps,
Denis