Yup! tRASmin or tRAS-minimum you can call it x) Its related to memory timings and latency..
The min number of cycles needed to access the rows or memory pages of your ram I suppose!
My ram clocks are 9-9-9-24-2T sum the ratings up like this tCL-tRCD-tRP-tRAS-CR
So my tRAS is 24 Clocks here which means my ram's pages or rows are going to be accessed in 24 clock cycles.
for better performance, it is better to lower the timing cycle!