First read one of the following articles depending on the version you are using:
Many of the files are optional.
To reduce the size of the SyncBackSE.exe file itself you can use free executable compressors suchs as UPX. To reduce the executables size (by around 75%) use the following command line with UPX:
upx -9 -f SyncBackSE.exe -o SyncBackSEUPX.exe
This will produce a file called SyncBackSEUPX.exe which is considerably smaller than the original SyncBackSE.exe file but does exactly the same thing.