State Management :: Storing Large Data In Session State?

We have a scenario where we need to store large tables of data on Session in asp.net page. on a highlevel we have to store following data

1> A table (table 1) with 1000 rows and 8 to 10 columns.

2> A table(table 2) with 500 rows and 8 to 10 columns (actually user can add the data from table 1 to table 2, so as user keeps on adding from table 1 we remove the data and put it in table 2)

3> Another table(table 3) with 1000-1200 rows each having 3 columns.

We are having a webfarm, so we need to store it in either SateServer of Oracle DB,What would be the performance implications of storing such huge data on the server.

One more thing is at any point of time max of 70 -80 people will be accessing our website, so will this cause any performance degradation?