A lot will depend on how (if at all) the text files are structured, and what sort of information they contain. In some situations, you might find it useful to take the files onto the PC first and use either a text editor, or something like Excel to rearrange the format. If, for instance, it's one name/value entry per line (or can be arranged that way), then the File.ReadMap command will easily turn the text file into a Map in B4A, and you can then work through that adding entries to a database.
If the data is more of a multi-column format, then you might want to turn it into a CSV file (if it isn't already), and then you can either use the StringUtils library to load the CSV into a B4A list (an example here
http://www.b4x.com/android/forum/threads/best-way-to-import-csv-file-in-sqlite-db.34382/ ) or make the database on your desktop using an SQLite tool, and simply include it as an asset with the project.
The choice for the latter will depend on what you really mean by the data built up - is this data that you, personally, have built up, so is entirely in your possession, in which case you can probably do things faster and easier on the PC. Or is it data that users of your app have built up themselves, in which case it may be less trouble to code your app to do the conversion for them, so it's a painless experience for each one.