  We report on the discovery of eight repeating fast radio burst (FRB) sources
found using the Canadian Hydrogen Intensity Mapping Experiment (CHIME)
telescope. These sources span a dispersion measure (DM) range of 103.5 to 1281
pc cm$^{-3}$. They display varying degrees of activity: six sources were
detected twice, another three times, and one ten times. These eight repeating
FRBs likely represent the bright and/or high-rate end of a distribution of
infrequently repeating sources. For all sources, we determine sky coordinates
with uncertainties of $\sim$10$^\prime$. FRB 180916.J0158+65 has a
burst-averaged DM = $349.2 \pm 0.3$ pc cm$^{-3}$ and a low DM excess over the
modelled Galactic maximum (as low as $\sim$20 pc cm$^{-3}$); this source also
has a Faraday rotation measure (RM) of $-114.6 \pm 0.6$ rad m$^{-2}$, much
lower than the RM measured for FRB 121102. FRB 181030.J1054+73 has the lowest
DM for a repeater, $103.5 \pm 0.3$ pc cm$^{-3}$, with a DM excess of $\sim$ 70
pc cm$^{-3}$. Both sources are interesting targets for multi-wavelength
follow-up due to their apparent proximity. The DM distribution of our repeater
sample is statistically indistinguishable from that of the first 12 CHIME/FRB
sources that have not repeated. We find, with 4$\sigma$ significance, that
repeater bursts are generally wider than those of CHIME/FRB bursts that have
not repeated, suggesting different emission mechanisms. Our repeater events
show complex morphologies that are reminiscent of the first two discovered
repeating FRBs. The repetitive behavior of these sources will enable
interferometric localizations and subsequent host galaxy identifications.
