This issue has been fixed in dbFront version 1.1.5.0013.
dbFront "intelligently" allowed for full like searches on tables smaller than 10,000 rows but forced you to specifically enter %keyword% when the tables were larger. I realized this was causing confusion.
The reason for this functionality is that doing a [LIKE "%keyword%"] search automatically forces your database to perform a full table scan. For small tables this is manageable by a decent database server. On larger tables this can cause significant performance issues.
This update to dbFront adds a setting where you the Admin can decide at what point users need to manually use the %keyword% syntax. The setting FullLikeRowLimit is found in the [Help] / [Settings] dialog under the service tab. See: Default Wildcard
In addition this release of dbFront is smarter about distributing the search across the various columns, some of which might be full-text indexed and others which might not be.
If you need your users to perform full-text searches on larger tables (1 million rows+) then you may want to enable Full-Text search.