Scope is usually local or global i.e. local to the block, global is across all blocks.
Initial value is a value set initially when downloaded to the PLC
Data Type is for example integer word, real (float) double integer, bit etc.
Symbolic name is it's symbol i.e. can be refered to by symbol or actual address.
Not sure what they mean by absolute address but assumes this refers to actual address in memory but could mean Bit area, DB area I/O area, this is not clear however, assuming this means common to Siemens that's probably what it means, in some other PLC's for example the absolute address refers to it's location in memory i.e. D100 could be 24565 decimal. Like Mistsubishi the data is fixed in banks within the memory area, Siemens is slightly different, for example DB's are like files on a disk, when a block is downloaded it is placed in spare memory, there is a sort of file allocation table (FAT) where the absolute address is stored, when you call a DB the PLC looks at the Fat table to find the actual start address, this applies to PB's,FB's, FC's as well (not quite so sure on S7 but was for S5 so assume it is similar).