in excel file you should have coordinates (LONGITUDE and LATITUDE) in decimal format. Open MapInfo, open excel file, on “Excel Information” dialog box check “Use row above……for Column Titles”,on “Set field properties” click OK (unless you like to change field type for each field) and a table appears. That’s a TAB file. If you like to show in the map, click Table-Create Points, select the table, Get X Coordinate from Column (that is column with longitude) Get Y Coordinate from Column (that is column from latitude), click “Projection …”, Category=Longitude/Latitude, Category Members=Longitude/Latitude (WGS 84), OK, OK and that’s it. Hope it helps.
I assume you’re doing some queries in MapInfo. If field type, for example BCCH, is “Character” and in the query you look for a number then you get the message you mentioned. The type of a column(field) and the type of value given in the query should be same. Check field type (such as BCCH) and declare as “Small Integer” and then run query giving the value as numbers. In MapInfo: Table-Maintenance-Table Structure …
Hope it helps,