Here are some examples of using tmultin:
stilts tmultin nin=3 in1=t1.xml ifmt1=votable
in2=t2.fit ifmt2=fits
in3=t3.txt ifmt3=ascii
out=tables.fits
stilts tmultin nin=3 in1=data.fits icmd1='every 10; head 100'
in2=data.fits icmd2='every 100; head 100'
in3=data.fits icmd3='every 1000; head 100'
out=samples.xml ofmt=votable