In a bivariate distribution the data are fairly large ,they must be summarized in the form of a two way table. Here for each variable the values are grouped into various classes( not necessarily the same for both the variable) keeping in view the same consideration as in the case of univariate distribution.
Eg. If there are m classes for the x variable series and n classes for the y variable series then there will be m*n cells in the two way table. By going through the different pairs of the values(x,y) and using tally marks we can find the frequency for each cell and thus obtained the so called bivariate frequency table .