rsdb/esm/max_objects is a SAP Parameter attribute which is used to control Maximum number of objects in ESM buffer information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Specifies the maximum number of objects that can be simultaneously held
in the export to/import from shared memory buffer. If this limit is
exceeded, it is not possible to store any more objects in the buffer. To
estimate a suitable value for the parameter, divide the size of the
buffer (see parameter rsdb/esm/buffersize_kb) by the expected average
size of the individual objects. Round up the value produced by this
See SAP Parameter Documentation for full SAP documentation for this profile parameter.