In your case you have one part category per tab. So in theory one tab could be imported into one MyElecParts part category if the category matches. In MyElecParts there are 3 capacitor categories by default I assume you have only one. Maybe splitting your input per MyElecParts part categories and importing one category at once could work, but still need a mapping of which columns goes into which fields.
I think many people use excel for this purpose, so an import feature would be great.
Perhaps a well defined format of the excel file could work with one part category per tab and one column per MyElecParts fields/parameters. Anyone who wants to use this feature would have to move their data into the appropriate tabs and columns. This is how it can work. Unfortunately, importing any arbitrary format is not possible.
Yesterday I went to test your program on a Win7 machine, but it told me I needed to download something. I wasn't near Internet access, so I couldn't proceed to test your program.
Having said this, I'm still flying blind on the suggestions I make.
Maybe others have a more elaborate spreadsheet than I. Mine started basic, but noticed different components required different columns/categories (I know I'm repeating). As a result, it began growing with general columns being common throughout the tabs, but other tabs had more columns to cater to the component.
Attached are a few pages from my file. To the far right is a column labeled 'Project Used On'. I use this as a way to remember just what the part is to spark a memory. Sometimes the part was used on a specific project, other times it may be inventory tossed out from a job.
If you plan to move forward with an import feature, a "notes" column may benefit most as I'd use it for the column in my spreadsheet labeled 'Project Used On'. In many cases, I use this column as notes anyway, but it's important because it helps me visualize the actual part.
I'll gladly help with an import feature such as suggesting column titles. If you make an import feature, then the user such as I, could make every tab have the same column titles. Any columns and/or cells that don't have information would either require something like N/A, blank, or whatever makes it easier to import into your program (unless you make your import feature recognize blank cells and will leave that area blank in your program without crashing it).
Looking at my spreadsheet, you can see the general categories are:
Component type, company, component, part number, value, mounting type, voltage rating, wattage, vin, vout, etc...
To elaborate on what I stated above, for my 'Cables' tab, I don't have a 'Vin' category, but it's needed for something like a voltage regulator. This is why different tabs have different columns. Technically I could make every tab the same, but felt it would make each tab too large and waste space.
To import correctly, I'd change my Excel sheet to make every tab have the same column titles. As you can see though, it's important to have a variety of column titles to cover all the types of components.
Also, I have a 'MISC' tab that may be a bit more difficult to import and maybe worth just skipping. These are random parts that may be mechanical hardware or whatever.