I think this question is more of a personal preference, but I would use XML in this case. You can have the structure predefined with distribution of your app, and modify/write the file at runtime. Its easy to read and understand, and just as easily modified. Simply universal. Sqlite has its positives in large forms of data, but can be much more complex for something that doesn't need much detail.
<index>
<category name="fruit">
<item>apple</item>
.....
</category>
......
</index>
A simple for loop through the categories, and see if the item is present, else add it.
Hope this helps, happy coding!