I am converting an .xls file (500kb) to a .csv (150KB) then using this to generate a MapInfo .tab file format using both QGis and ArcGIS. I can use an intermediate file ie. mif/mid format which gives a file size of about 250KB in both cases however when I convert this to .tab format I get a .dat file of about 6MB (the .id, .map and .tab total 14KB) using both programs. Note that QGis will not allow me to generate the .tab without generating a .mif first. Zipping these for emailing drops the size from about 6MB to less than 500KB so lot of empty space somewhere.
Have looked within the text files (.csv and the .mif/mid) but see no issues. I have used this method before on an older versions of this.xls file to generate MI format files totaling less than half a meg without any issues.
Any suggestions as to what is going on? Currently have no access to MapInfo to try.