These are ASCII files. First lines is a header followed by data for each halo. Halo data start after the line 'Number of centers ...' Each halo occupies one line. Numbers in that line are:

x,y,z , Vx,Vy,Vz, Mvirial, Rvirial, Vrms, Vcirc, Nparticles, RmaxVcirc, halo concentration

xyz are in Mpch units
vxyz - velocities in km/s
Mvir - halo mass (either virial or truncation) in Msun/h
Rvir - halo radius (virial or truncation) in kpch
Vrms - rms velocities of dm particles
Vcirc - current max circular velocity in km/s
Nparticles - number of particles in this halo
RmaxVcirc - radius of the max circular velocity in kpc/h
Halo concentration - Max(Rvir/RmaxVcirc*2.15,4.3)

Here are first few lines for the last snapshot, which explain meaning of different entries:

Header=>N=256x4096L250n2048s8=0.82 cambWMAP z80
A= 1.000 Step= 0.003
I = 416 Nrow=4096 Ngrid= 256
Omega_0= 0.270 Omega_L= 0.730 h= 0.700 Buffer zone (Mpch)= 3.143
Number of centers with radii between 0.0123 0.0135 was 475565
with radii between 0.0135 0.0645 was 2620653
with radii between 0.0645 0.0717 was 206072
Small halos with Mass(M_sun/h) less than 0.674E+09(N_eff< 0.619E+07) were removed
Minimum Radius of Halo(Mpc/h)= 0.0001 Minimum distance beteen halos(kpc/h)=10.0000
Comov.Search radius(Mpc/h)= 0.0700 Second radius(Mpc/h)= 0.0120
Particles with V> 1.0V_escape were removed Cell (in grids) for linker list= 0.223
Statistics for 107355977 points. Maxima= 447389
Box(Mpc)= 250.0 Overdensity Limit= 360.8 Cell for linker list(grids)= 0.223
Radii of shells in comoving kpc/h:
4.00 6.25 9.00 12.25 16.00 20.25 25.00 30.25 36.00 42.25
49.00 56.25 64.00 72.25 81.00 90.25 100.00 110.25 121.00 132.25
144.00 156.25 169.00 182.25 196.00 210.25 225.00 240.25 256.00 272.25
289.00 306.25 324.00 342.25 361.00 380.25 400.00 420.25 441.00 462.25
484.00 506.25 529.00 552.25 576.00 600.25 625.00 650.25 676.00 702.25
729.00 756.25 784.00 812.25 841.00 870.25 900.00 930.25 961.00 992.25
1024.00 1056.25 1089.00 1122.25 1156.00 1190.25 1225.00 1260.25 1296.00 1332.25
1369.00 1406.25 1444.00 1482.25 1521.00 1560.25 1600.00 1640.25 1681.00 1722.25
1764.00 1806.25 1849.00 1892.25 1936.00 1980.25 2025.00 2070.25 2116.00 2162.25

Number of centers= 104842 Velocity Duplicates: dR(Mpc/h)< 0.750 dV/Vrms< 0.150
6.9159 0.2869 0.1329 211.3 -341.7 -13.7 0.293E+10 29.80 13.6 21.8 21 14.9 4.30
15.0844 1.7259 0.1174 -15.4 -204.4 -44.5 0.696E+11 85.75 76.4 87.0 516 6.2 29.50
36.4723 1.5696 0.0728 -225.4 105.6 -19.0 0.105E+11 45.72 31.9 39.6 77 16.0 6.14
4.4087 1.8678 0.1406 320.2 -252.0 -90.4 0.347E+10 31.63 20.1 27.9 25 9.0 7.56
0.2325 2.1224 0.1145 292.9 -184.4 -108.0 0.343E+10 31.54 21.6 33.5 25 6.2 10.85